Find the Discriminant 2x(x-3)=x-5

$2 x (x - 3) = x - 5$

Step 1

Move all terms to the left side of the equation and simplify.

Simplify the left side.

Simplify $2 x (x - 3)$ .

Apply the distributive property.

$2 x \cdot x + 2 x \cdot - 3 = x - 5$

Multiply $x$ by $x$ by adding the exponents.

Move $x$ .

$2 (x \cdot x) + 2 x \cdot - 3 = x - 5$

Multiply $x$ by $x$ .

$2 x^{2} + 2 x \cdot - 3 = x - 5$

Multiply $- 3$ by $2$ .

$2 x^{2} - 6 x = x - 5$

Move all the expressions to the left side of the equation.

Subtract $x$ from both sides of the equation.

$2 x^{2} - 6 x - x = - 5$

Add $5$ to both sides of the equation.

$2 x^{2} - 6 x - x + 5 = 0$

Subtract $x$ from $- 6 x$ .

$2 x^{2} - 7 x + 5 = 0$

Step 2

The discriminant of a quadratic is the expression inside the radical of the quadratic formula.

$b^{2} - 4 (a c)$

Step 3

Substitute in the values of $a$ , $b$ , and $c$ .

${(- 7)}^{2} - 4 (2 \cdot 5)$

Step 4

Evaluate the result to find the discriminant.

Simplify each term.

Raise $- 7$ to the power of $2$ .

$49 - 4 (2 \cdot 5)$

Multiply $- 4 (2 \cdot 5)$ .

Multiply $2$ by $5$ .

$49 - 4 \cdot 10$

Multiply $- 4$ by $10$ .

$49 - 40$

Subtract $40$ from $49$ .

$9$