Question

Expand the following, using suitable identities: (–3x + 6y – 7z) 2

Answer 1

Answer:

ANSWER

(−2x+5y−3z)2 is of the form (a+b+c)2

(a+b+c)2=a2+b2+c2+2ab+2bc+2ca

where a=−2x,b=5y,c=−3z

∴(−2x+5y−3z)2=(−2x)2+(5y)2+(−3z)2+2(−2x)(5y)+2(5y)(−3z)+2(−3z)(−2x)

=4x2+25y2+9z2−20xy−30yz+12zx.