Factorise fully 2x^2 -x -4=2 and thus solve for x

Recall that to solve a quadratic it needs to be in the form ax2 + bx +c = 0, Subtract 2 from each side to get 2x2-x-6=0 therefore a=2 b=-1 and c=-6 Solve by considering factors c and a that expand out to equal b: 2 is a prime number and so must have 2 and 1 as the x coefficients and c can have factors -6&1 , -1&6, -3&2 and -2&3Use these to determine which combination expand to give b2x multiplied by -2 gives -4x and x multiplied by 3 is 3x which when added together gives -x which is what we want
Therefore the answer is (2x+3)(x-2)=0 therefore either bracket must equal 0 and so x=-3/2 or x=2

Answered by Lucy S. Maths tutor

2235 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the quadratic equation (x^2)-x-12=0 (easy), (x^2)-9=0 (special case), (x^2)+5x-13=0 (quadratic formula)


Karen got 32 out of 80 on a Maths test. She got 38% on an English test. Which test did she do better in?


Which of these fractions is the largest - 33/56 ,4/7, 9/21, 6/14


How find the values of x when x^2+8x+16=0?


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