4a+10=38 solve the equation

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

The number of calories you burn depends on your weight. a 110-pound person burns 163 calories during 30 minutes of tennis. find the number of calories that a 190-pound person would burn during the same activity, assuming they burn calories at the same rate.