for [tex]ax^2+bx+c[/tex] if a≠1 then first seee if you can undsitribute a ifyou can't use the ac method
multiply a and c find 2 numbers that add to b and multiply to get ac split b into that group undistribute undistribute
so
[tex]4x^2-7x-15[/tex] ac=4*-15=-60 what 2 numbers multiply to get -60 and add to get -7? 5 and -12 split b up into -12 and 5 [tex]4x^2-12x+5x-15[/tex] group [tex](4x^2-12x)+(5x-15)[/tex] undistribute [tex]4x(x-3)+5(x-3)[/tex] undistribute [tex](4x+5)(x-3)[/tex]
