Question 1148019
let x be the length of the extended spring.
you get x = 55 + .40 * 55 = 55 * (1 + .40) = 55 * 1.40 = 77.
the length of the extended spring will be 77 cm.
the original length of the spring is 55 cm.
the spring is stretched an additional 77 - 55 = 22 cm
22/55 = .4 * 100 = 40%
the spring is stretched by 40% of its original length.