Question

2a2+ b2 + c2 + 4ab - a2 + 3ac - 5ab – 4ac – bc. a=1 b=2 c=-1

Answer 1

Answer:

=2*(1)²+2²+(-1)²+4*1*2-1²+3*1*(-1)-5*1*2-4*1*(-1)-2*(-1)

=2+4+1+8-1-3-10+4+2

=21-14

=7