Question

Solve. 4x+5y=40

3x=15

POSSIBLE ANSWERS:
1. x=5, y=−12
2. x=5, y=−4
3. x=5, y=4
4. x=5, y=12

Answer 1

Solve for X first using the second equation.
3x = 15
x=15/3
x=5

OR if you were super lazy in this case, they practically gave you what x is based on the choices of answers given (They are all the same....5)

Plug it into the first equation and solve for y.
4(5)+5y=40
20+5y=40
5y= 40-20
5y=20
y=4

That would be choice 3.

Answer 2

Answer:4(5) + 5(4)=40 ...3(5)=15

So 20+20=40 ...15=15

I Say Answer Is 3. X=5, Y=4

Explanation: