Question

Expand : (5a-7b-12c)^2

Answer 1

Answer:

the answer is

Step-by-step explanation:

(5a-7b-12c)^2

identity =(a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca

(5a)^2+(-7b)^2+(-12c)^2+2×5a×(-7b)+2×(-7b)×(-12c)+2×(-12c)×5a

=25a +49b+144c+(-70ab)+168bc+(-120ca)

=25a+49b+144c-70ab+168bc-120ca