Question

Factorise
1) x²+ 9x + 18
2) 6x² + 7x - 3
3) 2x² - 7x - 15
4) 84 - 2r - 2r²​

Answer 1

Answer:

i) x2+9x+18=x2+3x+6x+18

=x(x+3)+6(x+3)

=(x+3)(x+6)

ii) 6x2+7x−3=6x2+9x−2x−3

=3x(2x+3)−1(2x+3)

=(3x−1)(2x+3)

iii). 2x2−7x−15=2x2−10x+3x−15

=2x(x−5)+3(x−5)

=(x−5)(2x+3)

iv). 84−2r−2r2=−(2r2+2r−84)

=−(2r2+14r+12r−84)

=−(2r(r+7)−12(r+7))

=−(r+7)(2r−12)

i hope this will help you

plz mark me as a brainliest answer.

Answer 2

1. x2 + 9x + 18

= x2 + 6x + 3x +18

= x( x+6) +3 (x+ 6)

= ( x + 3 )( x + 6)

2.6x2 + 7x - 3

=6x2 + 2x - 9x - 3

= 2x ( 3x + 1) - 3 ( 3x + 1 )

= ( 2x - 3 )(3x + 1 )

3.2x2 - 7x - 15

=2x2 - 10x + 3x - 15

= 2x ( x - 5 ) + 3 ( x - 5 )

= ( 2x + 3 )( x - 5 )

4.84 - 2r - 2r2

=2( 42 - r - r2 )

= -2 ( r2 + r - 42 )

= -2( r2 + 7r - 6r - 42 )

=-2 ( r ( r + 7) -6 ( r + 7) )

= -2 ( r+ 7) ( r - 6 )

= 2 ( r+ 7) ( 6 - r)

hope it helps plz mark me as brainliest ❤️