What is the constant of variation, k, of the line y = kx through (3,18) and (5,30)?

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

What is the solution to the division problem below x3+x2-11x+4/x+4

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)