Every day Maria spent 30 minutes reading and 20 minutes playing the piano witch equation shows the total number of minutes, m she plays the piano in d days

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b