Answer:
x=4 y=0
Step-by-step explanation:
3x+5y=12
-(x-3y=4)
3x+5y=12
3(-x+3y=-4)
3x+5y=12
-3x+9y=-12
14y=0
y=0
Then, substitute the y into the equation to find x
x-3(0)=4
x=4
Width of the rectangle is x + 3 in
Step-by-step explanation:
- Step 1: Given area of the rectangle = 3x² + 9x in². Length = 3x in. Find width.
Area = length × width
3x² + 9x = 3x × width
∴ Width = 3x² + 9x/3x = x + 3 in