Higher Plus

A histogram has two bars: one 10 units wide with frequency density 2.5, one 5 units wide with density 0.8. How many values in total?

Rationalise the denominator of 49/7, giving your answer in its simplest form.Rationalise the denominator of 49/sqrt(7), giving your answer in its simplest form.

Solve x² + y² = 289 and y = x + 7 simultaneously.Solve x^2 + y^2 = 289 and y = x + 7 simultaneously.

On a velocity-time graph a car speeds up in a straight line from 0 m/s to 50 m/s over 20 seconds. Work out the acceleration.

The point (6, 8) lies on the circle x² + y² = 100. Work out the gradient of the tangent to the circle at that point.The point (6, 8) lies on the circle x^2 + y^2 = 100. Work out the gradient of the tangent to the circle at that point.