Question

Simplify the following expressions and find their values if a = 1, b = 2 and c = -1 in 2a²++b²+c²+4ab-a²+3ac_5ab-5ab-4ac-bc (anser is 7)​

Answer 1

2a²+b²+c²+4ab-a²+3ac-5ab-4ac-bc

=2×1+(2)²+(-1)²+4×1×2-1+3×1×(-1)-5×1×2-4×1×(-1)-2×(-1)

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

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

=21-14

=7 ans

hope it helps and by the way i think you typed your question mistakely so i changed the question if there was no mistake in your question ,sorry!!