What is the value of x if x^2 - 3x +2=0?

This question can be difficult to see where to start, but can be quite easily solved once you realise what you have to do Firstly, let ax2+ bx + c =0. If this is also true, a=1, b= -3, and c=2. 

Firstly, find the factors of a*c (= 2). You will find there are only two, 1 and 2, or -1 and -2. 

First take the pair 1 and 2, and see if there is a way to add these together to make b. You will see that there are no ways to add or subtract these numbers from each other to get -3.

Now try with the second pair, -1 and -2. You will see that -1+-2=-3, and so this is the pair we want. 

 Therefore, (x-1)(x-2)=0

If we now solve this new factorised equation, we can see that either (x-1)=0 or (x-2)=0. Now rearrange to get the answers.

(x-1)=0                OR              (x-2)=0

x=1                      OR               x=2

CS

Related Maths GCSE answers

All answers ▸

Three different brands of rice are on sale, which brand provides the best value for money? Their prices are: Brand A) 250g for £3.21, Brand B) 400g for £5.30, Brand C) 750g for £8.80


Find x. x^2 + 6x + 5


How do I find the expression for the nth term in a series of numbers?


The area of a rectangle is 8cm^2. The rectangle is (3x+1) by (2x+5). Find the value of x