Step-by-step explanation:
the first equation gives us
5y = 4x - 49
y = (4x - 49)/5
that we use in the second equation
7(4x - 49)/5 + 2x = -23
(28x - 343)/5 + 2x = -23
28x - 343 + 10x = -115
38x = 228
x = 6
