1i) solve x^2-4x-21=0

Factorise to get (x+3)(x-7)=0 
So you can see that x = -3 or x =7 

Answered by Kishwar I. Maths tutor

3285 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How to complete the square to find the value of x?


Kieran, Jermaine and Chris play football. Kieran has scored 8 more goals than Chris. Jermaine has scored 5 more goals than Kieran. Altogether they have scored 72 goals. How many goals did Jermaine score?


n is an integer such that 3n+2<14 and 6n > n2 +5. Find all the values of n.


There are only 7 blue pens, 4 green pens and 6 red pens in a box. One pen is taken at random from the box. Write down the probability that this pen is blue.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences