A piece of lead for a mechanical pencil is 3.15 × 10–4 meter in diameter. What is the diameter of the lead in standard notation?
A.
31,500,000 meters

B.
3,150 meters

C.
0.000315 meter

D.
0.0000315 meter

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

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?

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?