How to find y-intercept of 2x - 5y + 15

If kn = 9 cm, mn = 21 cm, rs = 42 cm, and ps = 18 cm, what is the scale factor of figure klmn to figure pqrs?

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.

Chose the graph below that represents the following system of inequality’s