Algebra Examples

$f (x) = 3 x^{2} + 4 x$ at $x = - 2$

Step 1

Replace the variable $x$ with $- 2$ in the expression.

$f (- 2) = 3 {(- 2)}^{2} + 4 (- 2)$

Step 2

Simplify the result.

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Step 2.1

Simplify each term.

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Step 2.1.1

Raise $- 2$ to the power of $2$ .

$f (- 2) = 3 \cdot 4 + 4 (- 2)$

Step 2.1.2

Multiply $3$ by $4$ .

$f (- 2) = 12 + 4 (- 2)$

Step 2.1.3

Multiply $4$ by $- 2$ .

$f (- 2) = 12 - 8$

Step 2.2

Subtract $8$ from $12$ .

$f (- 2) = 4$

Step 2.3

The final answer is $4$ .

$4$

Step 3