Question

A rectangle of Length (4x-1) cm and Breadth (2x), has an Area 10 cm² find x

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Answer 1

x = 1.25

Explanation:

Givens

Area = L * w

L = 4x-1

w = 2x

Area = 10 cm^2

Formula

A = L * w

Area = 2x(4x - 1)

Solution

Area = 2x (4x - 1) = 10 Remove the brackets

2x * 4x - 2x = 10 Subtract 10 from both sides

8x^2 - 2x - 10 = 0 Factor

This factors into

(4x - 5)(2x + 2) = 0

4x - 5 = 0

4x = 5

x = 5/4

x = 1.25

2x + 2 = 0

2x = -2

x = - 1 When talking about area, this is an impossible answer.