Question

Evaluate 8x² + 2x + 5 when x = 7.

a) 403
b) 413
c) 323
d) 223

Answer 1

Substituting
`\(x = 7\)` into
`\(8x^2 + 2x + 5\)` yields
`\(411\)`, which is the correct evaluation, making the answer
`\(b) 413\)` inaccurate.

Step-by-step explanation:

To evaluate
`\(8x^2 + 2x + 5\)` when
`\(x = 7\)`, substitute x with 7 in the expression:

`\[8 \cdot (7)^2 + 2 \cdot 7 + 5\]`

Simplify each term:

`\[8 \cdot 49 + 14 + 5\]`

Calculate the products:

`\[392 + 14 + 5\]`

Combine the terms:

`\[411\]`

So,
`\(8x^2 + 2x + 5\)` when
`\(x = 7\)` is equal to 411. Therefore, option b) 413 is incorrect, and the correct answer is 411.