The Total solution for NCERT class 6-12
a2 + b2 + 2(ab + bc + ca)= a2 + b2 + 2 ab + 2 bc + 2 ca= (a + b)2 + 2c(b + a)= (a + b)2 + 2c(a + b)= (a + b) (a + b + 2c)