Answer:
This uses the method of elimination/addition.
Step-by-step explanation:
1 (9x + 7y = 15)
-7 (5x + y = -9) <— let’s eliminate y for both equations
9x + 7y = 15
+ -35x - 7y = 63 <— add both of the equations
—————————————————
- 26x + 0y = 6
(Please let me know if the answer is correct or not)
The answer is 8.031 per person
Answer:

Step-by-step explanation:
Let the number be x;
The product of 4 and the number will be;

The the square of the number is given as;

Taking the difference of both expressions above;

Factor out the common term:

Hence the difference between the product of 4 and a number and the square of the number is 
Answer:
X = -2 - y/3
Step-by-step explanation:
First you need to know the current equation, for that:
Notice that when Y = 0, X = 2.
When Y = 6, X = 0
Therefore the equation is X = 
To move that to the left of the X axis (negative direction) you just have to reduce the X number:

Answer:
The correct answer is actually around 21%. Are you sure the question wasn't asking what the approximate percent decrease from 85 to 70 was? Because in that case it would be around 17%.
Step-by-step explanation: