Question

1. which one doesnt belong? circle the expression that does not equal 13 when $x = 3$.

$5x - 2$ $5x^2 - 27 + 5$
$(x^3 - 1) \div 2$ $x + 13 - x$

Explanation:

Step1: Evaluate \(5x - 2\) when \(x = 3\)

Substitute \(x = 3\) into \(5x - 2\): \(5\times3 - 2 = 15 - 2 = 13\)

Step2: Evaluate \(5x^2 - 27 + 5\) when \(x = 3\)

First, calculate \(x^2 = 3^2 = 9\), then substitute: \(5\times9 - 27 + 5 = 45 - 27 + 5 = 23\)

Step3: Evaluate \((x^3 - 1)\div2\) when \(x = 3\)

Calculate \(x^3 = 3^3 = 27\), then substitute: \((27 - 1)\div2 = 26\div2 = 13\)

Step4: Evaluate \(x + 13 - x\) when \(x = 3\)

Simplify the expression: \(x - x + 13 = 13\)

Answer:

The expression that does not equal 13 when \(x = 3\) is \(5x^2 - 27 + 5\)