Solve the quadratic equation x^2+5x+6=0

There are two approaches which can be taken when solving this equation. The first is using the quadratic equation. By comparing the coefficients of the example to the general quadratic equation, a(x^2)+b(x)+c=0, we can set a=1, b=5 and c=6. We will now use the quadratic formula,x=(-b±√(b^2-4ac))/2a, and the values of a, b and c. Therefore, x==(-5±√(5^2-4x1x6))/2x1 We get that x=3 or x=2. The second approach is to use trial and error to find a pair of numbers which sum to 5 and whose product is 6, let us call these numbers d and e. Therefore, we need to find d and e such that b=d+e=5 and c=de=6. If these are satisfied, x=d or x=e. After trialling the possible pairs, 3 and 2 are a suitable pair, hence x=3 or x=2.

Answered by Anna M. Maths tutor

24838 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

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


Simplify √ 12 + √ 75


Solve the simultaneous equations: (1) x^2 + y^2=41 and (2) y=2x-3


How do I rewrite algebraic fractions as a single fraction?


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