Question

(3a)² + (2b)² + (5c)²​

Answer 1

Step-by-step explanation:

We have (x+y+z) ^2 =x ^2+y ^2 +z ^2

+2(xy+yz+zx)

Take x=3a,y=−2b and z=5c

(3a−2b+5c) ^2=(3a) ^2+(−2b) ^2+(5c) ^2+2(3a×−2b+(−2b)×5c+5c×3a)

=9a ^2 +4b ^2 +25c ^2 +2(−6ab−10bc+15ac)

=9a ^2 +4b ^2 +25c ^2 −12ab−20bc+30ac

∴(3a−2b+5c) ^2=9a ^2+4b ^2+25c ^2 −12ab−20bc+30ac