This is your information... Length: 2x + 7 Width: 3x + 8y Perimeter: 2(l + w) ...or... 2l + 2w Now let's substitute... 2(l + w) l = 2x + 7 w = 3x + 8y 2(2x+7+3x+8y) Now combine the like terms: 2(5x+7+8y) Now distribute the number 2: 10x+14+16y That is the perimeter I HOPE THIS HELPED!!!! :D ;D