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5 votes
Which of the binomials below is a factor of this trinomial?

4x^2-7x-15
O A. 2x-5
O B. 4x+5
O C. 2x+5
O D. 4x-5

User Cunners
by
5.3k points

2 Answers

3 votes

Answer:

B

Explanation:

Given

4x² - 7x - 15

To factorise the quadratic

Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term.

product = 4 × - 15 = - 60 and sum = - 7

The factors are - 12 and + 5

Use these factors to split the x- term

4x² - 12x + 5x - 15 ( factor the first/second and third/fourth terms )

= 4x(x - 3) + 5(x - 3) ← factor out (x - 3) from each term

= (x - 3)(4x + 5) ← in factored form

Hence 4x + 5 is a factor of the trinomial → B

User Kevin Simple
by
4.9k points
3 votes

Answer:

(x-3)(4x+5)

Explanation:

4x2−12x+5x−15

=4x(x−3)+5(x−3)

=(x−3)(4x+5)

User Prateek Yadav
by
5.4k points
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