Find the value of X in the equation X^2 + 9X - 22 = 0

There are 3 ways of solving this but I will go through the 2 that are necessary for GCSE level
Firstly - 22 can only be made by 122 or 211 -------> 11 - 2 = 9 therefore 11 and -2 are needed to make the roots of the equation------> (x + 11)(x-2)=0 --------> for the equation to equal 0 either x+11 or x-2 has to equal 0 -------> therefore x= -11 or x=2
Second way: quadratic formula - this one is best for when the numbers are not as nice as the example and the roots would involve a lot of decimal places
Use the formula (-b +/- _/b^2-4ac)/2a where the equation takes the form aX^2 + bX + c = 0 -------> values should be substituted in and the same answers should be found - This can be explained a lot better in the interview
Overall the answer is X = -11 or +2

CA
Answered by Christopher A. Maths tutor

3948 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the inequality 7x+3y-4 > 5y-19x for y in terms of x.


how would you expand quadratic factors


(a) The equation of a line L is 2x-3y=6. Find the gradient of L. (b) Find the equation of the line which is parallel to L and passes through the point (6,9)


May you please help me solve these algebra problem set ?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences