When a mathematician writes QED at the end of a proof, what does this mean?
O A. The proof cannot be completed.
OB. The proof needs more reasons.
O C. The proof is done.
O D. The proof is too long.

Sketch the region enclosed by the given curves. decide whether to integrate with respect to x or y. draw a typical approximating rectangle and label its height and width. y= 5x, y=7x^2then find the area s of the region.

Simplify using positive exponents only.

Walking at a constant rate of 8 kilometers per hour, juan can cross a bridge in 6 minutes. what is the length of the bridge in meters?