2x^2-6x+5 can be written in the form a(x -b)^ 2 + c where a, b and c are positive numbers. Find a,b and c.

In order to solve this problem we must first complete the square. To complete the square we need to factorise the equation to get the coefficient of x to be 1. This gives: 2(x^2-3x)+5. We then need to complete the square for x^2-3x. This gives: 2((x-1.5)^2-(1.5)^2)+5=2((x-1.5)^2-2.25)+5. [When completing the square we need to half the coefficient of x and minus it from x^2, we then change the x^2 to x and square this. We then minus the value of the coefficient squared from the squared brackets.] We finally need to simplify: 2((x-1.5)^2-2.25)+5=2(x-1.5)^2-4.5+5=2(x-1.5)^2+0.5. So from the initial question this gives a=2, b=1.5, c=-0.5.

CH
Answered by Chloe H. Maths tutor

21577 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

(ii) In 90 days, the gas used by a family cost $198.16 . Calculate the number of units of gas used.


How do I go about adding, subtracting, multiplying and dividing fractions?


x – 7x + 10 = 0


Rearrange aq - ac = d


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