Find the solutions to this quadratic equation: 0 = 2x^2 - 5x - 3
First we need to factorise this quadratic. This will be in the form:
0 = (Ax + B)(Cx + D)
You can work this out the values of A, B, C and D by looking at the coefficients in the unfactorised form. For example, you know that A x C = 2 as this is the coefficient of x^2, therefore the only two options for A and C are 1 and 2. You also know that B x D = -3, so you know that B and D must be +/-3 and +/-1. From here you can use trial and error to see with value is which.
0 = (2x + 1)(x - 3)
We know that for this to equal zero, either (2x + 1)=0, or (x-3)=0, so x=-0.5 and x=3
KB
Related Maths GCSE answers
All answers ▸What about simultaneous equations?
Natasha has two bags of fruit. both bags have the same number of fruit in total. 1/3rd of the fruit in bag 1 are apples and 15% of the fruit in bag 2 are apples. There are 20 apples in bag 1, how many apples are in bag 2?
If we take a fair 6 sided die and colour 3 of the faces blue, 2 green and 1 red and then roll the die 300 times, work out and estimate the number of times it will land with the green side up.
Expand and simplify (3x-1)(2x+1)(5-x)