Respuesta :

Answer:

AB = 75 cm

Step-by-step explanation:

Since ABC is a straight line, then

AB + BC = AC

let BC be x then AB = 5x and summing gives

5x + x = 90

6x = 90 ( divide both sides by 6 )

x = 15

Thus

AB = 5x = 5 × 15 = 75 cm