How can you use mental math to determine that 2800 divide equals 400

David uses $4.50 of his $6.00 to buy a sandwich what percent did he use

Explain the difference in the final product of (a + b) ^2 and (a - b) ^2.

What number must be multiplied by each side of the equation (2) / (5) x=10 to produce the equivalent equation x=25

In a complete sentence, write down a method you could use to determine if an equation is written in the correct way.

Between what two consecutive integers is the negative square root of 52

How do you add and subtract decimals as easily as you do whole numbers?

Whar is the value of x (x+1) + (2x-15)

Expand then simplify 2 (x-5) + 2x

A set of speakers costs $22 and songs cost $1.25 each. The sales tax rate is 7.5%. The expression 0.075 (22 + 1.25s) can be used to determine the amount of sales tax due on the entire purchase.

The lengths of nails produced in a factory are normally distributed with a mean of 5.13 centimeters and a standard deviation of 0.04 centimeters. find the two lengths that separate the top 8% and the bottom 8%.