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What is the value of 4x2 + 5x - 8, if x = 3?

1 Answer

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Answer: 43

Explanation:

Concept:

Here, we need to understand the idea of evaluation.

When encountering questions that gave you an expression with variables, then stated: "If x = a, y = b, z = c" (a, b, c are all constants), this means you should substitute the value given for each variable back to the expression.

Solve:

**Disclaimer** I assume that the expression is [4x² + 5x - 8]. If it was, then you may refer to my answer. If it was not, then you may point it out and I will redo it.

Given

4x² + 5x - 8

x = 3

Substitute the value of x

4(3)² + 5(3) - 8

Simplify exponents

4(9) + 5(3) - 8

Simplify multiplication

36 + 15 - 8

Final subtraction and addition

43

Hope this helps!! :)

Please let me know if you have any questions

User IGP
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