(m+5)(m+7)+m的二次方-25 等于多少啊!急,急
问题描述：
(m+5)(m+7)+m的二次方-25 等于多少啊!急,急
答
(m+5)(m+7)+m的二次方-25 = (m+5)(m+7) + (m+5)(m-5)
=(m+5)(m+7+m-5)
=2(m+5)(m+1)=2m^2 + 12m + 10
答
(m+5)(m+7)+m的二次方-25
=m^2+12m+35+m^2-25
=2m^2+12m+10
=2(m^2+6m+5)
=2(m+1)(m+5)