Question

expand by using suitable identity.​

Answer 1

Answer:

4a²+9b²+4c²+12ab+24bc+16ca

Answer 2

(x+y+z)2=x2+y2+z2+2xy+2yz+2zx,

On comparing (x+y+z)2 with (2a+3b+5)2,

x=2a,y=3b and z=5

Now, by using above identity,

(2a+3b+5)2=(2a)2+(3b)2+(5)2+2(2a)(3b)+2(3b)(5)+2(5)(2a)

                           =4a2+9b2+25+12ab+30b+20a

Hope this method helps.