Question

a) (2x - 3)(x - 5)

b) (x + 2y)(x - 2y)

c) (3x + 5y)²

d) (x - 1)²

Answer 1

A)
= (2x - 3)(x - 5)
= 2x.x + 2x.(-5) - 3.x - 3.(-5)
= 2x² - 10x - 3x + 15
= 2x² - 13x + 15

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b)
= (x + 2y)(x - 2y)
= x.x + x.(-2y) + x.2y - 2y.2y
= x² - 2xy + 2xy - 4y²
= x² - 4y²

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c)
= (3x + 5y)²
= (3x)² + 2.3x.5y + (5y)²
= 9x² + 30xy + 25y²

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d)
= (x - 1)²
= x² - 2.1.x + 1²
= x² - 2x + 1