Solve the following 1-step equation for x

If the average of x, y and z is 15 what is their sum

The volume of a rectangular prism is found by multiplying the length, width, and height of the prism. a rectangular prism has a width of 5x^2units, a length of 7x^3 units and a height of 2x^4 units. which is the volume of the prism in terms of x?

Leila is buying a dinosaur model. the price of the model is xxx dollars, and she also has to pay a 7\%7%7, percent tax.