Question

How do you factor `y^2 + 0.2y - 0.15`?

Answer 1

`y^2+0.2y-0.15=(y+0.5)(y-0.3)`

Explanation:

Note that `5*3 = 15` and `5-3 = 2`. We use this later...

If we let `x=0.1` then:

`y^2+0.2y-0.15`

`=y^2+2xy-15x^2`

`=(y+5x)(y-3x)`

`=(y+0.5)(y-0.3)`