Question

Factor y=5x^2-30x-135

Answer 1

`\boxed{\sf y =5(x-9)(x+3)}`

Explanation:

`\sf \textsf{Factor of y }=5x^2-30x-135.`

Solution:

`\sf y =5x^2-30x-135.`

Takin common 5

`\sf y=5(x^2-6x-27) \: ....... [i]`

Doing middle term factorization

`\sf (x^2-6x-27)`

`\sf x^2 -(9-3)x -27`

`\sf x^2 - 9x + 3x -27`

Taking common from each two terms

`\sf x(x-9) +3(x-9)`

taking common again and keeping remaining in another bracket

`\sf (x-9)(x+3)`

Substituting this in equation [i].

`\sf y=5(x-9)(x+3)`

`\sf \textsf{Therefore, Factor of y }=5(x-9)(x+3)`