1. What is the solution of the system?

Question

4x + 3y = 12
7x + 5y = 26

A. (18, 20)
B. (18, -20)
C. (-20, 18)
D. (20, 18)

Answer 1

multiply first equation by 5
and
the second equation by 3
20 x + 15 y = 60
21 x + 15 y = 78
------------------subtract
-1 x = - 18
so
x = 18
now go back and find y

Answer 2

4x+3y=12
7x+5y=26

B:18,-20