If x is positive and X/9 =4/x what is the value of x

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

Abarbecue sold 26 hamburgers and hot dogs. hamburgers sell for $3.50 each and hot dogs sell for $2.00 each. if the barbecue made $70 in sales, determine and state the number of hot dogs sold.

If the scale factor between two circles is 2x/5y what is the ratio of their areas?