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facrorise 2x^2- x- 1 please explain..
Question
facrorise 2x^2- x- 1
please explain..
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Mathematics
5 years
2021-07-30T07:57:24+00:00
2021-07-30T07:57:24+00:00 1 Answers
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Answers ( )
Answer:
(x – 1)(2x + 1)
Step-by-step explanation:
Given
2x² – x – 1
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 = 2 × – 1 = – 2 and sum = – 1
The factors are – 2 and + 1
Use these factors to split the x- term
2x² – 2x + x – 1 ( factor the first/second and third/fourth terms )
2x(x – 1) + 1 (x – 1) ← factor out (x – 1) from each term
= (x – 1)(2x + 1) ← in factored form