how do you solve the y-8x=66, 9y+x=10 with the substitution method

Question

how do you solve this using the substitution method?

y-8x=66

9y+x=10

Answer 1

Substitution method

y-8x = 66

Add 8x to each side.

y-8x+8x = 66+8x

y = 66+8x -------> (1)

Given second equation 9y+x = 10

From (1) substittute the y value.

9(66+8x)+x  = 10

594+72x+x = 10

594+73x = 10

Subract 94 to each side.

594-594+73x = 10-594

73x = -584

Divide to each side by 73.

73x/73  = -584/73

x = -8

Subsitute the x value in (1).

y = 66+8*-8

y = 66-64

y = 2

Solution x = -8, y = 2.