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