Question

Factorise
6x² + 31x +18
​

Answer 1

ANSWER:

• Factorisation of the above expression is (2x+9)(3x+2)

GIVEN:

• 6x²+31x+18

TO FIND:

• Factorise the above expression.

SOLUTION:

= 6x²+31x+18

= 6x²+27x+4x+18

= (6x²+27x)+(4x+18)

= 3x(2x+9)+2(2x+9)

= (2x+9)(3x+2)

Factorisation of the above expression is (2x+9)(3x+2).

NOTE:

Some important formulas:

(a+b)² = a²+b²+2ab

(a-b)² = a²+b²-2ab

(a+b)(a-b) = a²-b²

(a+b)³ = a³+b³+3ab(a+b)

(a-b)³ = a³-b³-3ab(a-b)

a³+b³ = (a+b)(a²+b²-ab)

a³-b³ = (a-b)(a²+b²+ab)

(a+b)² = (a-b)²+4ab

(a-b)² = (a+b)²-4ab