Substitute y = 1/5 x + 1 into x + 5y = -15
x + 5y = -15
x + 5(1/5 x + 1) = -15
x + x + 5 = -15
2x = -20
x = -10
Plug in x = -10 into y = 1/5 x + 1
y = 1/5 (-10) + 1
y = -2 + 1
y = -1
(-10 , -1)
Answer is the last one
