Question

How many solutions for linear equation 3x + 5y = 25 can be found so that −20 < y < 10, and x is an integer?

Answer 1

50

Explanation:

3x = 25 - 5y

-100 < 5y < 50

-50 < -5y < 100

-25 < 25 - 5y < 125

-8.333 < x < 41.667

41+8+1 = 50