What is the value of b in this diagram?

Apparently, you are to make use of the law of sines. It tells you

  b/sin(B) = a/sin(A)

You can multiply by sin(B) to find b.

  b = sin(B)·a/sin(A)

Substituting given values, this becomes

  b = sin(40°)·7.89/sin(121.5°)

  b ≈ 5.95

The Law of Sines looks like this:

b a

=

sin B sin A

Here we know the values of a, A and B:

b 7.89

=

sin 40 sin 121.5

7.89*sin 40 deg

Cross-multiplying, we get b =

sin 121.5 deg

21/58.

hope to be marked brainliest

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3