f(x)=x^2+12x+32=0, solve for x

Method 1: Quadratic formulaf(x)= ax2+bx+c, therefore a=1, b=12, c=32 - quadratic formula= (-b+/-(b2-4ac)1/2)/2ax=(-12+(144-128)1/2/2 = -4 or x=(-12-(144-128)1/2)/2 = -8
Method 2: FactoriseWe need to find a pair of numbers that when added make 12 and when multiplied make 32, 8 and 4 are our numbersTherefore f(x) can be written as (x+8)(x+4)The solutions to x are the numbers that make either bracket equal to 0, therefore x=-8 or x=-4

Answered by Maths tutor

3931 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations: (a) y - 2x = 6; (b) y+2x = 0.


What is a stratified sample?


Expand (x+4)(x-4)=33 to give values of x


Write x^2 - 6x +7 in the form (x+a)^2 +b


We're here to help

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

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning