# Using quadratic formula to solve quadratic equations

### Using quadratic formula to solve quadratic equations

Not sure if you should solve the quadratic equation by factoring or completing the square? No worries. You can always use the quadratic formula. The beauty of the quadratic formula is that it can always give you the answer no matter if the quadratic equations can be factored or not.

#### Lessons

Quadratic Formula
For the quadratic equation: $a{x^2} + bx + c = 0$
the solutions are: $x = \frac{{ - b\; \pm \;\sqrt {{b^2} - 4ac} }}{{2a}}$
• Introduction
Solve the equation using the quadratic formula:
$2{x^2} - 12x + 10 = 0$

• 1.
Solving a quadratic equation with TWO REAL SOLUTIONS
Solve using the quadratic formula: $x^2+10x+6=0$

• 2.
Solving a quadratic equation with ONE (REPEATED) REAL SOLUTION
Solve using the quadratic formula: $9x^2+25=30x$

• 3.
Solving a quadratic equation with TWO COMPLEX SOLUTIONS
Solve using the quadratic formula: $-3x^2-24x=49$