21,400 in standard form

Define a variable, write an inequality, and solve each problem:Twice a number is more than the sum of that number and 9

Convert 0.725 into a percent

There are 12 inches in 1 foot. what fact family would you use to find the number of inches in 2 feet?

Saturn has how many rings

Find the area of an equilateral triangle (regular 3-gon) with the given measurement. 6-inch side.

Fine two consecutive even integers such that twice the smaller is 26 more than the larger.

The ratio of zebras to elephants at the zoo is 6:5. The ratio of Gorillaz two zeros is 7:2. There are 30 zebras at the zoo. How many elephants are there? How many gorillas are there

A telephone number consists of seven digits, the first three representing the exchange. how many different telephone numbers are possible within the 537 exchange? the answer is.

Kenny's weight is 6/7 times Melvin's weight. How many times the total weight of the two boys in Kenny's weight?

The area of a semicircle is 2 times the area of a circle. True or False?