Factorize; (2x + 3y) 2 - (x - 4y) 2

Correct Answer is : (3x - y)(x + 7y)

Correct Answer is : (3x - y)(x + 7y)

Test Index

WAEC Mathematics 2016 Paper

Question : 14

Total: 49

Factorize; (2x + 3y)² - (x - 4y)²

Solution:

Concept:

Use the difference of two squares formula:

a^2 - b^2 = (a - b)(a + b)

Explanation:

Let

a = (2x + 3y)

and

b = (x - 4y)

Then the expression becomes

a^2 - b^2

Apply the identity:

(a - b)(a + b)

First bracket:

(2x + 3y) - (x - 4y) = 2x + 3y - x + 4y = x + 7y

Second bracket:

(2x + 3y) + (x - 4y) = 2x + 3y + x - 4y = 3x - y

Multiply the results:

(3x - y)(x + 7y)

This matches option A.

Answer:

(3x - y)(x + 7y)

, i.e. option A.

Go to Question:

Prev Question

Next Question