8x+9y=111, y=x+1

Question

solve this using the substitution method

Answer 1

Problem: 8x+9y=111, y=x+1
solve this using the substitution method

8x + 9y = 111
y = x + 1

8x + 9y = 111
8x + 9(x + 1) = 111
8x + 9x + 9 = 111
17x + 9 - 9 = 111 - 9
17x = 102
17x/17 = 102/17
x = 6

y = x + 1
y = 6 + 1
y = 7

Check.

8x + 9y = 111
8(6) + 9(7) = 111
48 + 63 = 111
111 = 111

Answer: x = 6, y = 7