a triangle ABC has a right angle at A. AC is 7 cm longer than AB, BC is 2 cm longer than AC. Taking AB=y, find the length of the sides

Question

this is all the information I was given

Answer 1

Let y = the length of AB

Let y + 7 = the length of AC

Let y + 9 = the length of BC

a² + b² = c²

y² + (y + 7)² = (y + 9)²

y² + y² + 14x + 49 = y² + 18y + 81

2y² + + 14y + 49 = y² + 18y + 81

y² - 4y - 32 = 0

(y - 8)(y + 4) = 0

y - 8 = 0     or     y + 4 = 0

AB = 8 cm             y = -4, illogical answer

AC = 15 cm

BC = 17cm