Represent the following sentence as an algebraic expression, where "a number" is the letter x. 2 is multiplied by a number.

Abike shop sells you a bicycle for $63 and a helmet for $21. the total cost is 150% of what the shop spent originally. how much did the shop spend originally? how much profit did the bike shop earn by selling the bicycle and helmet to you ?

The perimeter of a quarter circle is 14.28 miles. what is the quarter circle's radius?

Round each decimal to the nearest thousandth. a. 5.39562 b. 0.12345 c. 5634 d. 18.93763