Search over 10,000 free study notes

When you add and subtract surds, the numbers inside the square root must be the same. You add/ subtract the number outside the square root. e.g. 2√5 + 7√5 = 9√5, however 2√5 + 7√3 cannot be added. when yo...

x²+y²=25, y-2x= 5 y = 5+2x  -----> y² = (5+2x)² = 25 + 20x +4x² x² + 4x² + 20x + 25 = 25 5x² + 20 x = 0 x = 0 y =...

a) (x+7)(x-7) b) y = (x^2) - 49 y' = 2x 0 = 2x x = 0 y = (0^2) - 49 y = -49, x = 0

The key here is to simplify the left hand side. There are two different approaches to take here, one slightly faster but both perfectly legitimate. First approach: Remember the formula (a + b)^{2} = a^{2}...

Simple interest means the amount of money increases by the same amount each year, compound interest means the amount of money increases by the same proportion each year. For example if you deposited £100 ...