Factorise 3x^2 + 14x + 8

To factorise polynomials of the form ax^2 + bx + c, we want to rewrite the middle coefficient as the sum of two smaller numbers. The product of these two numbers should be equal to a * c (in this case, 3 * 8 = 24), and the sum of the two numbers should equal b (in this case, 14). Here, we can see that the values 2 and 12 fit this criteria. Rewriting the original expression would then look like this: 3x^2 + 2x + 12x + 8
From here we can factorise by grouping together the first two terms and the last two terms. By taking the greatest common factor of each group, we get x(3x+2) + 4(3x+2). As (3x+2) appears in both terms here, we can further simplify to (x+4)(3x+2).

AM
Answered by Alex M. Maths tutor

13633 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Simplify fully (3x^2-8x-3)/(2x^2-6x)


Solve: a) 5t + 17 = 2. b) x^3 - 25 = 103 - x^3.


How do you calculate the area of a triangle when the question tells you the length of all three sides but no angles?


A different pattern is made using 20 straight lines and 16 arcs. The straight lines and arcs are made of metal. 20 straight lines cost £12 and the cost of one straight line: cost of one arc = 2:3. Work out the total cost of metal in the pattern.


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