How do i do Quadratic Formula easily?

Question

yanasidlinskiy · Answer

Is your question on how to use a Quadratic Formula?

pphalke · Answer

By using factoring and using structure

thesmartone · Answer

$\Large x = \frac{-b\pm \sqrt{b^2-4ac}}{2a}$

You just have to memorize the formula and plug in numbers and then simplify to get the final answer.

mathstudent55 · Answer

To help memorize the formula, every time you need to use the quadratic formula to solve the problem, write the quadratic formula before you substitute values for a, b, and c. By writing the formula many times, you wil end up memorizing it.

For example:

Problem:

Solve the following quadratic equation using the quadratic formula.

$\Large 2x^2 + 7x - 4=0$

Solution:

$\Large x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a} $


$\Large x = \dfrac{-7 \pm \sqrt{7^2 - 4(2)(-4)}}{2(2)} $

Etc.

By writing the quadratic formula, you will memorize it more easily, and you avoid mistakes when you substitute the coefficients into the quadratic formula. After you substitute the values in the second equation above, you just simplify the expression until you find the solutions.