How to calculate the rise and run of a slope (4,-1) and (-2,3)

The distance of a chord from the centre of a circle is 12cm and the lenght of the chord is 10cm. find the radius of the circle

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

Which equation is y = -6x2 + 3x + 2 rewritten in vertex form?