Change first equation
x - 2y = 1
add 2y to both side
x = 2y + 1
Plug into second equation
3(2y+1) - 6y = 3
Distributive property
6y + 3 - 6y = 3
y = 0, plug into first equation
x - 2(0) = 1, x = 1
Solution: x = 1, y = 0
The answer is 4. 2x plus 7 is equal to 15. First you subtract 7 from both sides then divide by 2 to get the answer 4. Hope this helps!
