1. (07.02) What is the value of x in the equation 2x + 9 = 21?

2
6
9
15

What is the equation of the graph that represents f(x)=x^4 stretched vertically by 2 and shifted up 3 spaces

Pls the last one and it has to be like number 6

The base of a rectangular pyramid is 13 inches long and 12 inches wide. the height of the pyramid is 8 inches. what is the volume of the pyramid