Find a tutor
How it works
Prices
Resources
For schools
Become a tutor
Answers
>
Maths
>
GCSE
>
Article
x^2 - 10x + 21 = 0
First, factorise the quadratic equation.
Find two numbers that multiply to give 21 and add to give 10. 7 and 3
(x-7)(x-3)=0
Now find the value x so that when these brackets are multiplied together the answer is 0.
So either x=7 or x=3
You can check the answer by substituting 7 and 3 into the equation.
BS
Answered by
Ben S.
•
Maths tutor
4109 Views
See similar Maths GCSE tutors
Related Maths GCSE answers
All answers ▸
expand and simplify (x+1)(x-1)
I'm good at maths, I swear
A ten-sided die with sides numbered 1-10 is thrown. What is the probability of throwing a 1?
How do you solve the equation 3(6x + 2) = 10 + 4x?
We're here to help
Contact us
Message us on Whatsapp
+44 (0) 203 773 6020
Company Information
Careers
Blog
Subject answers
Become a tutor
Schools
Safeguarding policy
FAQs
Using the Online Lesson Space
Testimonials & press
Sitemap
Popular Requests
Maths tutor
Chemistry tutor
Physics tutor
Biology tutor
English tutor
GCSE tutors
A level tutors
IB tutors
Physics & Maths tutors
Chemistry & Maths tutors
GCSE Maths tutors
© MyTutorWeb Ltd 2013–2025
Terms & Conditions
|
Privacy Policy
CLICK CEOP
Internet Safety
Payment Security
Cyber
Essentials
Cookie Preferences