Answer:
m=-29/3 and n=65/3
Step-by-step explanation:
The given system has equations:
3m+3n=36
8m+5n=31
Multiply the top equation by 5 and bottom equation by 3 to get:
15m+15n=180
24m+15n=93
Subtract the top equation from the bottom equation to get:
9m=-87
Divide both sides by 9

We substitute this value into the first equation to get:




Answer:
9.) 
10.) 
11.)
minutes of calling would make the two plans equal.
12.) Company B.
Step-by-step explanation:
Let <em>t</em> equal the total cost, and <em>m,</em> minutes.
Set up your models for questions 9 & 10 like this:
<em>total cost = (cost per minute)# of minutes + monthly fee</em>
Substitute your values for #9:

Substitute your values for #10:

__
To find how many minutes of calling would result in an equal total cost, we have to set the two models we just got equal to each other.

Let's subtract
from both sides of the equation:

Subtract
from both sides of the equation:

Divide by the coefficient of
, in this case: 

__
Let's substitute
minutes into both of our original models from questions 9 & 10 to see which one the person should choose (the cheaper one).
Company A:

Multiply.

Add.

Company B:

Multiply.

Add.

<em />
14.
Angles 4 and 6 are supplementary, because they are on the same line. Supplementary angles add up to 180 degrees, and a line must be 180 degrees.
15.
Angles 1 and 8 are congruent, because they are alternate exterior angles
16.
m = y2 - y1 / x2 - x1
m = 7 - 2 / 4 - 5
m = 5 / -1
m = -5
17.
m = 3 - 3 / 7 - (-5)
m = 0 / 12
m = 0
18.
m = 1 - (-2) / 5 - (-4)
m = 3 / 9
m = 1/3
19.
A = (0, 3) - B = (3,0)
m = 0 - 3 / 3 - 0
m = -3 / 3
<em>m = -1</em>
C = (0, -2) - D = (4, 2)
m = 2 - (-2) / 4 - 0
m = 4 / 4
<em>m = 1</em>
Perpendicular, because the slopes are opposite reciprocals.
20.
E = (1, 2) - F = (0, 0)
m = 0 - 2 / 0 - 1
m = -2 / -1
<em>m = 2</em>
G = (1, -3) - H = (3, 0)
m = 0 - (-3) / 3 - 1
<em>m = 3 / 2</em>
Neither, because the slopes are different.
21.
I = (0, 1) - J = (2, -4)
m = -4 - 1 / 2 - 0
<em>m = -5/2</em>
K = (-1, -2) - L = (4, 0)
m = 0 - (-2) / 4 - (-1)
<em>m = 2/5</em>
Perpendicular, because the slopes are opposite reciprocals.
22.
M = (-2, 2) - N = (2, 2)
Horizontal line
<em>m = 0</em>
O = (3, 0) - P = (-3, 0)
Horizontal line
<em>m = 0
</em>Parallel, because the slopes are the same.
<em>
</em>23.
Angle 2 is congruent to angle 1 because of the alternate exterior angle theorem.
Angle 1 is congruent to angle 3 because of the vertical angle theorem.
Angle 2 is congruent to angle 3 because of substitution.
Line l is parallel to line m because the corresponding angles are congruent.
Answer:
The investor receives $200
Step-by-step explanation:
In order to find this, simply multiply the percentage by the total amount.
$5,000 * 4%
$5,000 * .04
$200