Which value is needed in the expression below to create a perfect square trinomial?
1 answer:
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Answer:
A and E
Step-by-step explanation:
Given
20x² - 26x + 8 = 0 ( divide through by 2 )
10x² - 13x + 4 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 10 × 4 = 40 and sum = - 13
The factors are - 5 and - 8
Use these factors to split the x- term
10x² - 5x - 8x + 4 = 0 ( factor the first/second and third/fourth terms )
5x(2x - 1) - 4(2x - 1) = 0 ← factor out (2x - 1) from each term
(2x - 1)(5x - 4) = 0
Equate each factor to zero and solve for x
2x - 1 = 0 ⇒ 2x = 1 ⇒ x = → E
5x - 4 = 0 ⇒ 5x = 4 ⇒ x = → A