Evaluate x^2 +2x -4 = 0
Using the quadratic formula (-b +- sqrt(b^2 -4ac))/2a we can sub substitute a = 1, b=2 and c = -4 to solve. The answer is x = -1 +/- sqrt(5)
AC
Related Maths GCSE answers
All answers ▸One of the teachers at a school is chosen at random. The probability that this teacher is female is 3/5. There are 36 male teachers at the school. Work out the total number of teachers at the school.
Solve the simultaneous equations: [4x-y=3] and [6x +2y=1]
Equations
A trader buys 6 watches at £25 each. He scratches one of them, so he sells that one for £11. He sells the other 5 for £38 each. Find his profit as a percentage.