Divide (a2+7a+10) by (a+5).
Given: a2+7a+10(a+5) ...(i)
Comparing a2+7a+10 with the identity x2+(a+b)x+ab,
we note that,(a+b)=7 and ab=10
So, 5+2=7 and (5)(2)=10
Hence,
a2+7a+10
=a2+5a+2a+10
=a(a+5)+2(a+5)
=(a+2)(a+5)
From (i), we get
a2+7a+10(a+5)=(a+2)(a+5)(a+5)
=(a+2)