How do you find the surface area for a triangular pyramid

What is the standard form of -5x^2+2x^4-11+x^3+3x

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3

Af jewelry box is in the shape of a rectangular prism with an area of 528 cube inches. the length of the box is 12 inches and the height is 5 1/2 inches. what is the width of the jewelry box