How do you use the quadratic formula?

The equation for the quadratic formula is x = (-b +/- √(b^2 - 4ac))/2a for when the equation ax^2 + bx + c is equal to 0. When you have the equation ax^2 + bx + c, where a, b and c are given numbers, you can sub the numbers into the quadratic formula to find x.For example, you are given 2x^2 + 6x + 4 = 0 and asked to find x. Here you can see that a=2 , b=6 and c=4. You can then sub these into the quadratic formula to give x = (-6 +/- √(6^2 - 4(2)(4)))/2(2) and put this into your calculator to find that x = -2 or -1.

IB
Answered by Isla B. Maths tutor

2546 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How do you find the volume of a cylinder?


What is the gradient of a line with the equation y=4x+5?


Find the 16th term in the following sequence: 3, 5, 7, 9, 11


All tickets for a concert are the same price. Amy and Dan pay £63 altogether for some tickets. Amy pays £24.50 for 7 tickets. How many tickets does Dan buy?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning