Thanks Alan,
OR
You could solve it by completing the square method
x2−4xm+(2m−14)=0x2−4xm=−(2m−14)x2−4xm+(2m)2=−2m+14+(2m)2(x−2m)2=−2m+14+4m2(x−2m)2=4m2−2m+14(x−2m)2=4(m2−m2+116)(x−2m)2=4(m−14)2x−2m=±2(m−14)x=2m±2(m−14)x=2m+2m−12orx=2m−2m+12x=4m−12orx=12