standard_description: Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line.
problem_activity: Task
The product of two positive numbers is 9. The reciprocal of one of
these numbers is 4 times the reciprocal of the other number. What is
the sum of the two numbers?


aligns: no