Sin4θ - sin2θ =
2cos3θcosθ
2cos3θsinθ
2sin3θcosθ
2sin3θsinθ

B.  2cos3θsinθ.

Step-by-step explanation:

Use the identity

sin x - sin y   = 2 [cos(x + y)/2]sin [x - y)/2].

So we have:

sin4θ - sin2θ = 2 cos (4θ+2θ)/2 sin (4θ-2θ)/2

= 2cos3θsinθ.

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.