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# The total surface area of the walls of a room 7m long, 5m wide and xm high is 96...

### Question

The total surface area of the walls of a room 7m long, 5m wide and xm high is 96m2. Find the value of x

### Options

A) $$\frac{2}{3}$$

B) 2

C) 4

D) 8

### Explanation:

T.S.A of the wall $$=7\time 5 + 7 \times x + 5 \times x +7 \times 5 = 96\\70 + 7x + 5x = 96 \Rightarrow 12x = 96-70=26\\x = \frac{26}{12}=2$$

## Discussion (2)

• I appreciate the explanation but I don't understand.
• T.S.A of the wall $$=7\time 5 + 7 \times x + 5 \times x +7 \times 5 = 96\\70 + 7x + 5x = 96 \Rightarrow 12x = 96-70=26\\x = \frac{26}{12}=2$$