How do you write 31 billon in scientific notation

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

Acone with volume 1350 m³ is dilated by a scale factor of 1/3. what is the volume of the resulting cone? enter your answer in the box. m³

Ateacher brought a pack of 17 batteries . each calculator uses 3 batteries . how many calculator can the teacher fill with batteries