Question

Can someone help please, will give brainiest if correct!!!!

Answer 1

Answer:

AB = 4.5 cm

Step-by-step explanation:

Area = sum of areas of two rectangles

36 = [x(x - 4)] + [(x - 2)(2x + x)]

36 = x² - 4x + 3x² - 6x

4x² - 10x - 36 = 0

Dividing by 2:

2x² - 5x - 18 = 0

2x² - 9x + 4x - 18 = 0

x(2x - 9) + 2(2x - 9) = 0

(2x - 9)(x + 2) = 0

x = -2, 9/2

AB = x = 4½ cm

Answer 2

Answer:

AB = 9/2 cm

AB = 4.5 cm

Step-by-step explanation:

The area of small rectangle

x * (x-4) = x^2 -4x

The area of  the big rectangle

The height is 2x +x  and the width is x-2

(2x+x) * (x-2)

(3x) * (x-2)

3x^2 -6x

Add the areas together

x^2 -4x + 3x^2 -6x

4x^2 -10x

This is equal to 36

4x^2 -10x=36

Subtract 36 from each side

4x^2 -10x -36=36-36

4x^2 -10x-36=0

Divide each side by 2

2x^2 -5x -18=0

Factor

(x + 2) (2 x - 9) = 0

Using the zero product property

x+2=0  2x-9=0

x = -2   2x =9

x = -2   x = 9/2

Since we cant have a negative length

x = 9/2

AB = 9/2 cm