Question

What is the value of the expression below when z=2?

4z^2 -3z-4

Answer 1

6

Explanation:

Evaluate 4 z^2 - 3 z - 4 where z = 2:

4 z^2 - 3 z - 4 = 4×2^2 - 3×2 - 4

Hint: | Evaluate 2^2.

2^2 = 4:

4×4 - 3×2 - 4

Hint: | Multiply 4 and 4 together.

4×4 = 16:

16 - 3×2 - 4

Hint: | Multiply -3 and 2 together.

-3×2 = -6:

16 + -6 - 4

Hint: | Group the negative terms in 16 - 6 - 4 together and factor out the minus sign.

16 - 6 - 4 = 16 - (6 + 4):

16 - (6 + 4)

Hint: | Evaluate 6 + 4.

6 + 4 = 10:

16 - 10

Hint: | Subtract 10 from 16.

| 1 | 6

- | 1 | 0

| 0 | 6:

Answer: 6