How do I solve the equation x^2 = 3x - 1 ?

First, we need to rearrange the equation into a quadratic. A quadratic equation will always have a squared element. 

To this, we move everything over to the left hand side of the equation and set it equal to zero. (Remember: Change the side, change the sign)
So..
x^2 = 2x - 1

becomes..

x^2 - 2x = - 1
and then..

x^2 - 2x + 1 = 0

One way to solve this equation is by using factorisation.

the equation takes the form.. ax+ bx + c = 0 

we need to find two numbers that add together to make be and multiply together to make a x c.

So, numbers that add to -2 and multiply to 1 x 1 = 1.

These numbers are -1 and -1.

So we can factorise the equation.

Step 1..

x- x - x - 1 = 0

Step 2..

x(x-1) - 1(x-1) = 0

Step 3..

(x-1)(x-1) = 0

So to find x, we simply divide both sides of the equation by (x-1).

Leaving x - 1 = 0, so x = 1.

 

MW
Answered by Matthew W. Maths tutor

7900 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve simultaneously. x^2+y^2 = 25 ; y - 3x = 13


There are 200 students in Year 10 110 are boys. There are 250 students in Year 11 140 are boys. Which year has the greater proportion of boys? (Taken from Nov 2014 AQA Unit 2)


Solve the simultaneous equations: 5x + y = 21, x - 3y = 9


When would I use the quadratic formula?


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:

© 2025 by IXL Learning