Question

What is the value of 4a^3–2b^2+5 when a = 3 and b =–2

Answer 1

105

Explanation:

Evaluate 4 a^3 - 2 b^2 + 5 where a = 3 and b = -2:

4 a^3 - 2 b^2 + 5 = 4×3^3 - 2×(-2)^2 + 5

3^3 = 3×3^2:

4×3×3^2 - 2×(-2)^2 + 5

3^2 = 9:

4×3×9 - 2×(-2)^2 + 5

3×9 = 27:

4×27 - 2×(-2)^2 + 5

(-2)^2 = 4:

4×27 - 24 + 5

4×27 = 108:

108 - 2×4 + 5

-2×4 = -8:

108 + -8 + 5

| | 1 |

| 1 | 0 | 8

+ | | | 5

| 1 | 1 | 3:

113 - 8

| | 0 | 13

| 1 | 1 | 3

- | | | 8

| 1 | 0 | 5:

Answer: 105

Answer 2

105

Explanation:

4a^3 -2b^2 +5

Let a=3 and b= -2

4 (3)^3 -2 (-2)^2 +5

4 *27 -2 (4) +5

108 -8+5

105