As – 16a,
as – 4a3,
2a3 + 8a - 4a2 - 16

1) as-16a

taknig a as common

=a(s-16)

2)as-4a³

taking a as common

=a(s-4a²)

3)2a³+8a-4a²-16

taking common terms

=2a(a²+4)-4(a²+4)

=(2a-4)(a²+4)

again taking common

=2(a-2)(a²+4)

i hope this will help you :)

answer:   b

step-by-step explanation:

x2 = 16

x can not be a negative number because 16 is positive

the only answer would be positive 8