Question

Fortorise 2x² + x - 45​

Answer 1

Answer:

$= 2 {x}^{2} + x - 45 \\ = 2 {x}^{2} +10x - 9x - 45 \\ = 2x(x + 5) - 9(x + 5) \\ = (x + 5)(2x - 9)$

hence factorised

Answer 2

Required Answer:-

Given to factorise:

• 2x² + x - 45

Answer:

• The factorised form is (2x - 9)(x + 5)

Solution:

2x² + x - 45

= 2x² + 10x - 9x - 45

= 2x(x + 5) - 9(x + 5)

= (2x - 9)(x + 5)

Hence, the factorised form is (2x - 9)(x + 5)

How to factorise?

• The general form of a quadratic equation is ax² + bx + c where a, b and c are real numbers. We have to split b into two real numbers(say x and y) such that sum of those numbers is equal to b and product of those numbers is equal to ac.
• After splitting the middle term, we will factorise the Quadratic Polynomial by grouping method.
• Note: Since a quadratic polynomial is factorised by grouping method, it is also called middle term factorisation.