Question

How do you factor the trinomial `a^2-11ab-60b^2`?

Answer 1

`(a+4b)(a-15b)`

Explanation:

Note:`color(blue)((-15)+(4)=-11and(-15)*(4)=-60)`
So,
`a^2-color(red)(11ab)-60b^2=a^2color(red)(-15ab+4ab)-60b^2`
`=acolor(red)((a-15b))+4bcolor(red)((a-15b))=(a+4b)(a-15b).`