7x+2y=2
2x-y=10
what is the value of y?
a. y=-22
b. y=22
c. y=2
d. y=-6

7x+2y=2
2x-y=10

7x = 2-2y
x= (2-2y)/7eq. 1

By substituting the value of x in eq. 1
2 {(2-2y)/7} - y =10
{ (4 -4y)/7 } -y =10
( 4-4y -7y)/7=10
4- 11y = 70
-11y = 70-4
-11y = 66
y= -6

The value of y is -6 and so, option d is correct.

The value of y is -6. 

First, I figured out that the value of x is 2, so I plugged in two the the 2nd equation.
 
2(2) - y = 10 ⇒  4 - y = 10
                         - 4         - 4
                   
                            - y = 6
                           
                             -1   -1
 
                           y = -6