Why is the numbers with a 5 in the ones place not prime numbers

Sold 45 of his DVDs and purchased 10 more. If Smith has 15 DVDs now, how many DVDs did he have to begin with?

Using the graph, select an answer. Given an eight-year-old car, the difference between the car's value and its repair costs will be number.

What is the simplified form of 3a^4b^-2c^3

What is the circumference of a circle with a radius of 3 inches? Give your answer in terms of pi.

A boathouse costs $2750 a month to operate, and it spends $650 each month for every boat that it docks. The boathouse charges a monthly fee of $900 to dock a boat.

Classify each polynomial by its degree and number of terms. 7/4x+3 5.2x^2-4x=2.5 3/5 0.75x^2

Claire wants to place a mirror that is 1812 inches wide in the center of a wall that is 31 inches wide. How far from each corner should she place the mirror for it to be centered.

Three times the sum of a number and three

18. What value of b will make the equation have no solution? 6x + 4 = 4bx - 2

A circle has a sector with are of (17/2) pi and a central angle of (17/90) pi radians. What is the area of the circle? Either enter an exact answer in terms of pi or use 3.14 pi and enter your answer as a decimal.