Solve by factorisation: 2(x^2) - 5x - 12 = 0

First step is to multiply coefficient of first term (2) with the constant (-12) to enable us to split the middle term.2*(-12) = -24, therefore we need to find two numbers that multiply to -24, and add to give the coefficient of the second term (-5). These two numbers are -8 and 3 as these numbers add to give -5 and multiply to give -24. Therefore we can split the middle term: 2x2 - 8x + 3x - 12 = 0By factorising:2x(x - 4) + 3(x - 4) = 0, (x - 4)(2x + 3) = 0.If (x - 4) = 0, x = 4.If (2x + 3) = 0, x = - 1.5.Therefore, solutions for x for this quadratic equation are x = 4, -1.5.

EC

Related Maths GCSE answers

All answers ▸

Find the area of the rectangle, in cm, with width 4x and length (y+5). Then calculate the area for x = 7 and y = 8.


Edexcel November 2016 1H Maths. Q27


A graph is sketched with the equation x^2+4x-5. Find the minimum point of this graph.


Kieran, Jermaine and Chris play football. Kieran has scored 8 more goals than Chris. Jermaine has scored 5 more goals than Kieran. Altogether they have scored 72 goals. How many goals did Jermaine score?