Help. Please

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

This is about circle theorems. someone asap : (

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