Question

how to expand (2a+3b-4c)^2​

Answer 1

(x+y+z)²

=x² +y²+z² +2xy+2yz+2zx [Identity]

x=2a

y=3b

z=-4c

Putting Values in Identity, We get :

⇒ (2a+3b-4c)²

=(2a)²+(3b)² +(-4c)² +2(2a)(3b)+2(3b(-4c)+2(-4c)(2a)

=4a² +9b²+16c²+12ab-24bc-16ca