The donations by a restaurant to a certain charity, y, will be two-fifths of its profits, x, plus $50. How can you determine the equation in slope-intercept form that shows the relationship between x and y without graphing the line?

The equation would be y=(2/5)x+50.

Explanation:
Slope-intercept form is given by y=mx+b, where m is the slope and b is the y-intercept. The original $50 donated has nothing to do with the profits; if the profits are $0, they will still donate $50. This is the y-intercept, b.

Since they are donating 2/5 of their profits x, this means that the rate of change, or slope, of the line will be 2/5 of a dollar donated per dollar profit; this is m. Plugging these in gives us the equation above.