Question

How to do this question?

Answer 1

Let width of  each rectangle = x and the length = y. Area of 1 rectangle = 288/9 = 32. Then we have the following system of equations;  

xy = 32

3y (x + y) = 288

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Expanding the second equation:-

3xy + 3y^2 = 288

Substitute xy = 32 in the above equation:-

3*32 + 3y^2 = 288

3y^2 =  288 - 96 = 192

y^2 = 192/3 = 64

y = 8 , So x = 32/y = 32/8 = 4

The perimeter  = 2 (3*8) + 2( 4 + 8)

= 48 + 24

= 72 cm   Answer