What number must you add to complete the square? x2 - 20x = 17

The difference between tax advoidance and tax evasion

Scrub a dub toothbrushes are $4.00 each. there is a 10% discount, but there is also a 6% sales tax after the discount is applied. what is the new price after tax? round to the nearest penny

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.