Question

3. Factor each of the following polynomials using GCF and/or 2 binomials. Show your work. 4 points

A.5x^2 – 2x =
B.x^2 – 12x – 45 =
C.2x^2-x-15
D.9x^2-16​

Answer 1

Given :-

• A.5x^2 – 2x =
• B.x^2 – 12x – 45 =
• C.2x^2-x-15
• D.9x^2-16

To Find :-

• Factorised form into two binomials .

Answer :-

A) 5x² - 2x

= x ( 5x -2 )

B) x² - 12x -45

= x² -15x + 3x -45

= x(x -15) +3( x -15)

= (x-15) ( x +3)

C) 2x² - x -15

= 2x² +5x - 6x -15

= x(2x +5) -3(2x +5)

= (x-3)(2x+5)

D) 9x² -16

=(3x)² -4²

= (3x+4)(3x-4) [using a²-b² = (a+b)(a-b) ]

Answer 2

• See below

Explanation:

A

• 5x² – 2x = x(5x - 2)

B

• x² – 12x – 45 = x² + 3x - 15x - 45 = x(x + 3) - 15(x + 3) = (x + 3)(x - 15)

C

• 2x² - x - 15 = 2x² + 5x - 6x - 15 = x(2x + 5) - 3(2x + 5) = (2x + 5)(x - 3)

D

• 9x² - 16 = (3x)² - 4² = (3x + 4)(3x - 4)​