X^2+4x-21=0 Solve for x

Quadractics factorise into double brackets like (x-a)(x-b). We ave to find the facors of -21 which add to make +4. 7 and -3 suffice. (x-3)(x+7) Then x will be equal to 3 and -7 for the equation.

JC
Answered by James C. Maths tutor

3911 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Amanda and Wim share some money in the ratio 2:5. Wim receives £115. Calculate how much money was shared?


Write 8^2(4^2 / 2^7) in the form 2^x


Prove that (3n+1)²-(3n-1)² is a multiple of 4 taking into account that n is a positive integer value


The equation of the regression line of y (retail price, £) on x (number of pages) for a set of books is y = 0.02x + 1.35. How can I use this equation?


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences