Question

2. what is the solution of the system?

7x+5y=19
-7x-2y=-16

A. (2,1)
B. (1,2)
C. (7,5)
D. (-7,-2)

Answer 1

its A 
minus the two equations so that its becomes 3y=3
y=1
-7X-2x1=-16 
X=2

Answer 2

A。7x+（-7x）=0，5y+（-2y）=3，3y=3，y=1

7x+5=19，x=2