Question

10. A rectangle with area of 3cm2 has lengths
(x + 4)cm and (x + 2)cm. Find its dimensions.

Answer 1

Explanation:

We have (x + 4)(x + 2)cm² = 3cm².

=> x² + 6x + 8 = 3

=> x² + 6x + 5 = 0

=> (x + 5)(x + 1) = 0

=> x = -5 or x = -1

x = -5 is rejected as both side lengths would have negative values.

Therefore x = -1;

• (x + 4)cm = (-1 + 4)cm = 3cm
• (x + 2)cm = (-1 + 2)cm = 1cm

Hence the dimensions are 3cm by 1cm.