Answer:
study more so you can understand
9x+ 5y=35
2x + 5y=0 |* -1
9x +5y= 35
-2x -5y= 0
-----------------
7x / = 35
x=35:7
x=5
2x+5y=0
2*5+5y=0
10+5y=0
5y=-10
y= -10:5
y=-2
For this function we can find y-intercept.
x=0, y=-2
This graph is on the top, right.
a. The first variable is x and the second variable is y.
b. The equations are
and 
Step-by-step explanation:
Step 1:
The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.
Here let the first variable be x and the let the second variable be y.
So the variables are defined as x and y.
Step 2:
The sum of the given variables is 12.
The first variable + the second variable = 12,

The difference between the two variables is 4.
The first variable - the second variable = 4.

Step 3:
If we add both the equations we get,
and 
x = 8 and y = 4.