In 15 years, a child's age will be 9 years less than four times her current age. Find her current age.
On a certain trip, Edgar drives 231 km in exactly the same time as Erwin drives 308 km. If Erwin's rate exceeded that of Edgar by 13 kph. Determine the rate of Erwin.
If (4, b) is a point on the graph of y = 3x² + 4x, what is b?
If 4 times a number is increased by 16, the result is 8 less than 8 times the number. What is the number?