To solve for the equation 5a + 2b when a = 7/15 and b = -6/5, we substitute these values into the equation:

5(7/15) + 2(-6/5)
= 35/15 - 12/5
= (35 - 36)/15
= -1/15

Therefore, when a = 7/15 and b = -6/5, the result of the equation 5a + 2b is -1/15.