Answer:
Amount invested at 7% = 16000
Amount invested at 9% = 12000
Step-by-step explanation:
Let x be the amount invested at 7% and y be the amount invested at 9%.
Since the total amount invested is $28000, therefore, we can set up the first equation as:

Secondly, we are give that sum of two investments is $2200. Therefore, we can write the second equation as:

Now we need to solve these two equations to get the values of x and y.
First of all, we multiply the second equation with 100 in order to get rid of decimal values.

Let us use substitution method here. First of all we will solve for y from first equation and plug that into second equation.


Therefore, amount invested at 7% is $16000 and amount invested at 9% is 28000-16000=$12000.
37.
13 - 7 = 6
Her Mom Uses 6
38.
9 + 8 = 17
Andrew Had 17 Muffins
Answer:
F(4)=24 and F(3)=18
Step-by-step explanation:
Plug the 4 and the 3 in to the x's and multiply them by 6
The equation of the line passes through (2, -1) and (4, 5) is -3x + y = - 7 So, option 2 is correct.
<u>Solution:</u>
Given, two points are (2, -1) and (4, 5)
We have to find that a line that passes through the given two points.
First let us find the slope of the line that passes through given two points.
So, slope of line "m" is given as:


So slope of our line = 
Now, let us find the line equation using point slope form:

Then equation of line is,
y – 5 = 3(x – 4)
y – 5 = 3x – 12
-3x + y = 5 – 12
-3x + y = -7
Hence, the line equation is -3x + y = - 7 so, option 2 is correct.