Help help help help help m at h math math

9514 1404 393

Answer:

  (x, y) = (3, 12)

Step-by-step explanation:

The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.

We see that the second equation already has a variable with a coefficient of 1.

When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:

  y = 4x . . . . . . . add 4x to both sides of the second equation

Now, we have an expression for y that we can substitute into the first equation.

  2x +2(4x) = 30 . . . . substitute for y

  10x = 30 . . . . . . . . simplify

  x = 3 . . . . . . . . . . divde by 10

  y = 4(3) = 12 . . . . . find y using y=4x

The solution is (x, y) = (3, 12).

__

Additional comment

I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.

You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30   ⇒   y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.

The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.

After storing 5/9 in the large silo there was 4/9 left ( 1-5/9 = 4/9)

A. Multiply 4/9 by 3/4:

4/9 x 3/4 = 12/36 = 1/3

1/3 of the corn was in the small silo.

B. 1-5/9 -1/3 = 4/9-1/3 = 4/9-3/9 = 1/9

1/9 of the corn went to market:

18 x 1/9 = 18/9 = 2

2 ton went to market.

Answer:

Since we know the dot product of unit vectors, we can simplify the dot product formula to a⋅b=a1b1+a2b2+a3b3. we can use the same formula, but with a3=b3=0, a⋅b=a1b1+a2b2.

Step-by-step explanation:

9514 1404 393

Answer:

 (36°, 67°, 77°)

Step-by-step explanation:

The problem statement lets us write the equations ...

  x + y + z = 180 . . . . sum of angles in a triangle

  y + z = 4x . . . . . 2nd and 3rd total 4 times the first

  z = y +10 . . . . . . 3rd is 10 more than 2nd

__

Substituting for z in the second equation, we have ...

  y +(y +10) = 4x

  y +5 = 2x . . . . . . divide by 2

  y = 2x -5 . . . . . . rearranged

  z = 2x +5 . . . . . . substitute for y in the last equation

Now, we can write the first equation entirely in terms of x:

  x +(2x -5) +(2x +5) = 180

  5x = 180

  x = 36

  y = 2(36) -5 = 67

  z = 67 +10 = 77

The three angles are (x, y, z) = (36°, 67°, 77°).

Answer: the answer is 3

Step-by-step explanation:

I just took the test

Answer:

C- 35 °

Step-by-step explanation:

Interior angle adjacent to 90° angle = 90° (supplementary angles of a line segment).

Interior angle adjacent to 125° angle = 55° (supplementary angles of a line segment).

Sum of two interior angles of the triangle = 55+90 = 145°

∠p = 180° - 145° = 35°

Answer:

- 27.88

Step-by-step explanation:

Probability of earthquake = 0.0012

P(earthquake). = 0.0012

P(no earthquake) = 1 - p(earthquake) = 1 - 0.0012 = 0.9988

X ____ 60,000 ______ - 100

P(X) ___ 0.0012 _____ 0.9988

The expected value of the policy :

E(X) = Σx*p(x)

E(X) = (0.0012 * 60000) + (0.9988 * - 100)

E(X) = 72 - 99.88

E(X) = - 27.88

C-x=-5

Step-by-step explanation:

-3x=-15

or,-3x x =-15

or, x=-15÷3

therefore, x=-5

Answer:

A) 128

B) 7800

Step-by-step explanation:

Trial and error until I got to 75 x 104 and 60 x 128 (which abides by the fact that there has to be 24 more red boxes) which equals 7800 and 7680 and if you take them away from each other you get 120

Answer:

B. 24.

Step-by-step explanation:

3

4 = 2*2

6 = 2*3

8 = 2*2*2

LCM = 2*2*2*3 = 24

Answer:

Bayes’ Theorem describes the probability of occurrence of an event related to any condition. It is also considered for the case of conditional probability.

For prove refer to the attachment.

Hope this helps you^_^

Answer:

12

Step-by-step explanation:

πr²h=πr²h

π(4.5)²*10=π(x/2)²4.9

Answer:

m∠F = 45°

Step-by-step explanation:

Notice the lengths of the given sides and the right angle. This is enough information to prove that this is a 45-45-90 triangle, or just basically a square cut diagonally.

Regardless if even just one side is given for a 45-45-90 triangle, all 45-45-90 triangles have one thing in common. The sides that form the right angle are equivalent and the hypotenuse is equal to one of the sides that form the right angle times the square root of two. I'm aware that it sounded confusing, as I'm awful at explaining, so just look at the picture I've attached instead of trying to understand my explanation that seemed like trying to learn a second language.

Look at the picture. See that FD = x times that square root of 2 and that DE = x. Now look back at your picture. It's connecting, now isn't it?

Now that we know that this is indeed a 45-45-90 triangle, we can confirm that m∠F = 45°

Answer:

Step-by-step explanation:

x3−x2+5x−12

x

≥0

Let's find the critical points of the inequality.

x3−x2+5x−12

x

=0

x3−x2+5x−12=0(Multiply both sides by x)

(Use cubic formula)

x=1.836169

Check possible critical points.

x=1.836169(Works in original equation)

Critical points:

x=1.836169(Makes both sides equal)

x=0(Makes left denominator equal to 0)

Check intervals in between critical points. (Test values in the intervals to see if they work.)

x<0(Works in original inequality)

0<x≤1.836169(Doesn't work in original inequality)

x≥1.836169(Works in original inequality)

Answer:

x<0 or x≥1.836169

Answer:

u = 18

Step-by-step explanation:

The two angles 3u and u+36 are equal so

3u = u+36

Subtract u from each side

3u -u = u+36-u

2u = 38

Divide by 2

2u/2 = 36/2

u = 18

Answer:

27

Step-by-step explanation:

Let T be the capacity of the tank.

Since the tank was 1/3 full and ends up 7/9 full.

         [tex]\frac{7}{9}[/tex]T - [tex]\frac{1}{3}[/tex]T = 12  

Simplifying the left side of the equation, tells us how much 12 gallons fills.

         [tex]\frac{4}{9}[/tex]T = 12

Now we solve for T:

         T = 12*9/4

         T = 27

Step-by-step explanation:

Let the husband's income be x

Wife's income be x + 9000

X + X + 9000 = 81000

2X + 9000 – 9000 = 81000 – 9000

2X= 72000

X = 36000

Husband, 36000,

Wife, 9000+36000, 45000

The Minimum sample size table is attached below

Answer:

[tex]X=173[/tex]

Step-by-step explanation:

From the question we are told that:

Confidence Interval [tex]CI=99\%[/tex]

Variance [tex]\sigma^2=30\%[/tex]

Generally going through the table the

Minimum sample size is

[tex]X=173[/tex]

Answer:

5а⁶=а⁶+а⁶+а⁶+а⁶+а⁶

~~~~~~~~

Answer:

cannot understand the language man

but please follow

Answer:

75 inches

Step-by-step explanation:

with this we use change of subject

V=1/3

Pie=3.14

radius =3

height =8

so therefore

V=1/3 ×3.14×3×3×8

V=75.36

y = 2/3 x - 2

Or

y + 2 = 2/3 ( x )

Answer:

y= 2/3x - 2

hope this helps :)

Answer:

The mean is the average number of a data set gotten by adding all the numbers then dividing by two.

the median is the middle number in a sorted set of data,either sorted in ascending order or descending order.

I hope this helps

To calculate mean:

• add up all the numbers,

• then divide by how many numbers there are.

Example:

Data: 5, 6, 10, 1

Add these all together, which is 22, then divide by 4 (because that is how many numbers there are), so:

the mean is 5.5

To calculate median:

Arrange your numbers in order.

Cross off numbers until you get to the middle.

If there is an even number of data, then find the two in the middle and find the middle of that.

Example:

Data: 5, 6, 10, 1

Arrange: 1, 5, 6, 10

So, the middle 2 are 5 and 6. In between these would be 5.5, so that is the median.

If the data was: 1, 5, 6, 8, 10,

then the median would be 6.

Answer:

Click the graph in Quadrant 1

Step-by-step explanation:

This graph is bigger in side length.

Answer:

5180.56 Dollars...........

Answer:

at 15.39% that should not be sufficient to reject the Null

= "Fail to reject the Null hypothesis"

Step-by-step explanation:

z = -1.02 (L)0.15386 (R)0.84614

84.61% / 15.39%

Answer <1 = 145

< 2= 35

<3 = 35

Step-by-step explanation:

<1 + <4 = 180 (supplementary since you can find corresponding side and straight angle)

<1 = 180-35

=145 degrees

<2 =<4 corresponding angles

<2 = 35 degrees

<3 = 35 degree (corresponding to <2)

Answer:

is y=x^2 a proportional relationship?

[tex]{ \sf{yes. \: constant \: of \: proportionality = 1}}[/tex]

is y=2+x a proportional relationship?

[tex]{ \sf{no. \: unless \: y \: is \: proportinal \: to \: (2 + x)}}[/tex]

is y=2/x a proportional relationship?

[tex]{ \sf{yes. \: where \: proportianality \: constant \: is \: 2}}[/tex]

is y=2x a proportional relationship?

[tex]{ \sf{yeah. \: constant \: is \: 2}}[/tex]

Answer:

A. Increase the level of confidence

Step-by-step explanation:

The margin of error is given by:

The margin of error is:

[tex]M = \frac{Ts}{\sqrt{n}}[/tex]

In which T is related to the level of confidence(the higher the level of confidence, the higher T is), s is the standard deviation of the sample and n is the size of the sample.

Increase the width:

That is, increasing the margin of error, as the width is twice the margin of error, the possible options are:

Increase T -> increase confidence level.

Increase s -> Increase the standard deviation of the sample.

Decrease n -> Decrease the sample size.

Thus, the correct answer is given by option A.