5x = –25 + 5y ---> 5x - 5y = -25 (1)
10y = 42 + 2x ---> 2x - 10y = -42 (2)
divide equation (2) by 2
so
x - 5y = -21
now you have
5x - 5y = -25
x - 5y = -21
-----------------subtract
4x = -4
x = -1
substitute x = -1 into 5x - 5y = -25
5x - 5y = -25
5(-1) - 5y = -25
-5 - 5y = -25
-5y = -20
y = 4
answer
(-1 , 4)
