Question

How do you solve this using substitution method
17x+7y=20
Y=20x-42

Answer 1

17 x + 7 y = 20

y =20x - 42

17 x + 7(20x - 42) = 20

17x + 140x - 294 = 20

157 x = 20 + 294

157x ÷ 157 = 314 ÷ 157

x = 2

y = 20x - 42

y = 20 (2) - 42

y = 40 - 42

y = -2

there for x = 2 and y = -2 is the solution