Question:`xx^2` -2x -15
Answer
`xx^2` -2x -15 =`xx^2` -5x + 3x -15 =x(x-5)+3(x-5) =(x-5) (x+3)
Question:`xx^2` -2x -15
`xx^2` -2x -15 =`xx^2` -5x + 3x -15 =x(x-5)+3(x-5) =(x-5) (x+3)
Question:6`xx^2` + 11xy - 10`y^2`
6`xx^2` + 11xy - 10`y^2` =6`xx^2`+ 15xy - 4xy - 10`y^2` =3x(2x +5y) -2(2x+5y) =(3x-2y) (2x+5y)
Question:Factorise `y^2`- y - 42
`y^2`- y - 42 =`y^2`- 7y + 6y - 42 =y(y+7) + 6(y-7) =(y-7) (y+6)
Question:Factorise `x^2` - `y^2` and hence evaluate `100^2` - `99^2`
`x^2` - `y^2` =(x+y) (x-y) `:.` `100^2` - `99^2` =(100+99) (100-99) =199+1 =200
Question:By using the factors of `x^2` - `y^2`, evaluate `96^2` - 36
`x^2` - `y^2` =(x+y)(x-y) `:.` `96^2` - 36 = `96^2` - `6^2` =(96+6) (96-6) =102+90 =192