Find the value of the variable x in the equation x-21=8

A flock of mallard ducks and a flock of pintail ducks are swimming in a lake. there are 28 ducks in each flock. if half the ducks from the mallard flock leave the lake, what is the total number of ducks that will remain in the lake?

A factory makes 12 bags in three hours making both at the same rate how many bags would have made an eight hours

Suppose u and v are differentiable functions of x. use the given values of the functions and their derivatives to find the value of the indicated derivative.

What is the value of x? 3x - x + 4 = 4 (2x - 1)

The length of a rectangular mirror is 13 inches and the width is 39 inches. What is the perimeter?

How do I divide 2 fractions

There are 18 bicycles. There are more more blue than yellow. There are 2 less yellow than green. How many of each color are there?

Triangle STU is dilated to form new triangle VWX. If angle S is congruent to angle V, what other information will prove that the two triangles are similar?

What is the exact area of a circle with a radius of 11 feet?

How many batches of trail mix can Eric make with 16 cups of peanuts, 15 cups of raisins, and 8 cups of walnuts?