Question

Please Help 100 Points

Answer 1

Answer:

it's answer is 3x - 3

y + x - 8 + 8x + 4 = 12x - 7

y + 9x - 4 = 12 x - 7

y = 12x -9x - 7 +4

y = 3x - 3

hope it helps you

Answer 2

Answer:

$\Large \boxed{\sf 3x-3}$

Step-by-step explanation:

Perimeter is sum of all sides

Subtract both given sides from perimeter to get the missing side

$(12x-7)-( \ (x-8)+(8x+4) \ )=3x-3$