Higher Plus

On a histogram, a 4-wide bar and a 8-wide bar have the same frequency density of 2.5. How many more values are in the wider class?

x = 133 and y = 10, each correct to the nearest whole number. Work out the upper bound of x - y.

Write x² + 14x - 2 in the form (x + a)² + b.Write x^2 + 14x - 2 in the form (x + a)^2 + b.

A tram runs at 18 m/s for 20 s, then slows steadily to rest over 6 s. Work out its average speed for the whole journey, to 2 decimal places.

The point (9, 40) lies on the circle x² + y² = 1681. Work out the gradient of the tangent to the circle at that point.The point (9, 40) lies on the circle x^2 + y^2 = 1681. Work out the gradient of the tangent to the circle at that point.