[tex]8m^{2}+20m=12 / :2[/tex]
[tex]4m^{2}+10m=6[/tex]
[tex]4m^{2}+10m-6 =0[/tex]
[tex]\Delta=b^{2}-4ac[/tex]
[tex]\Delta=100-(4*4*-6)[/tex]
[tex]\Delta=100+96=196[/tex]
[tex]x1=\frac{-b-\sqrt{\Delta}}{8}[/tex]
[tex]x1=\frac{-10-14}{8}[/tex]
[tex]x1=\frac{-24}{8}[/tex]
[tex]x1=-3[/tex]
[tex]x1=\frac{-b+\sqrt{\Delta}}{8}[/tex]
[tex]x2=\frac{-10+14}{8}[/tex]
[tex]x2=\frac{1}{2}[/tex]
so you can write [tex]8m^{2}+20m=12 / :2[/tex] as
[tex]8(m+3)(m-\frac{1}{2})=8*[m^{2}+2.5m-1.5]=0[/tex]
