4а-15в-2при а=1/4, в=3/5

To find the value of the expression 4а - 15в - 2 when a = 1/4 and b = 3/5, substitute the given values into the expression:

4(1/4) - 15(3/5) - 2

Simplifying the expression:

1 - 45/5 - 2

1 - 9 - 2

-10

Therefore, when a = 1/4 and b = 3/5, the value of the expression 4а - 15в - 2 is -10.