Solve x^(2)-x-12

We must factorise. Find factor pairs of -12;1,-12;-1,12;2,-6;-2,6;3,-4;-3,4. Out of the pairs, we must find the pair that will add up to -1 - this is because of the '-x' part of the equation. The answer is 3 and -4. Now use this to factories; (x+3)(x-4). Check by expansion. Now make this equal to zero and solve for x; x=-3, x=4.

HK

Related Maths GCSE answers

All answers ▸

​What's the difference between the mean, median and mode? Why are there so many different types of average?!


Work out 2(3/4)*1(5/7). Give your answer in mixed number form.


[Higher] Simplify the following expressions: x^7 X x ^5 and (x^-2)^-3


2x^2-7x+3=0, solve the following for the two solutions of x