Evaluate f(x)=5x^2-7(4x+3)

$f (x) = 5 x^{2} - 7 (4 x + 3)$

Step 1

Simplify each term.

Apply the distributive property.

$f (x) = 5 x^{2} - 7 (4 x) - 7 \cdot 3$

Multiply $4$ by $- 7$ .

$f (x) = 5 x^{2} - 28 x - 7 \cdot 3$

Multiply $- 7$ by $3$ .

$f (x) = 5 x^{2} - 28 x - 21$

Step 2

Subtract $f (x)$ from both sides of the equation.

$0 = 5 x^{2} - 28 x - 21 - f (x)$

Step 3

Rewrite the equation as $5 x^{2} - 28 x - 21 - f (x) = 0$ .

$5 x^{2} - 28 x - 21 - f (x) = 0$