Question

In a rectangle ABCD if AB=4x and DC=7x-9,find the length of AB.(Lengths are in cm).

Answer 1

12 cm

Explanation:

AB and DC are parallel to each other, so they are the same length. Set their lengths equal to each other and solve for x

4x = 7x - 9

4x - 7x = 7x - 7x -9

-3x = -9

-3x/-3 = -9/-3

x = 3

Now solve for AB.

AB = 4x

AB = 4(3)

AB = 12