Which variable expression represents the phrase “3 times the sum of twice a number and 3”? a 3/2n+3 b 3 ⋅ 2n+3 c 3(2n+3) d 2n+3/3

Mary works for a company that ships packages and must measure the size of each box that needs to be shipped. mary measures a box and finds the length is 7 inches, the width is 14 inches, and the height is 15 inches. what is the volume of the box? [type your answer as a number.]

Solve the system of equations. 2x-2y=-4 and x+y=8. show work

Aliter of water contains about 3.35 x 10^25 molecules. a certain river discharges about 2.9x 10^8 l of water every second. about how many molecules does the river discharge every minute? write your answer in scientific notation