Answer:
x = 3, y = -1.
Explanation:
4x + 5y = 7
y = 3x - 10
Substitute for y = 3x - 10 in the first equation:
4x + 5(3x - 10) = 7
4x + 15x - 50 = 7
19x = 7 + 50 = 57
x = 57/19 = 3.
Now plug x = 3 in the second equation
y = 3(3) - 10
y = 9 -10
y = -1.