Question

How long will the length of the corner of a square arm increase by 5 cm?​

Answer 1

Answer:

Let the side of the original square = x.

(x+5)^2 = 4x^2

x^2+10x+25 = 4x^2

3x^2–10x-25 = 0

3x^2–15x+5x-25 = 0

3x(x-5)+5(x-5) = 0

(x-5)(3x+5) = 0

x = 5 or -(5/3) which is inadmissible.

Hence the side of the original square is 5 cm.

Check: Area of original = 5^2 = 25 sq cm.

(5+5)^2 = 10^2 = 100 sq cm which is 4 times the original square.