If 7x + 4y = 18 and 3x + y = -3, what is the value of x + y?

F. 9
G. 11
H. 12
J. 14
K. 15

5 answers

7x + 4y = 18
3x + y = -3

y = -3 -3x

7x + 4(-3 -3x) = 18
7x - 12 - 12x = 18
-5x = 18 + 12
-5x = 30
x = -6

3(-6) + y = -3
y = 18 - 3
y = 15

15 + (-6) = ?
15 - 6 = 9
Yes.
Thank you so much, Ms. Sue.
You're very welcome.