To simplify the expression, first distribute the negative sign in front of the parentheses:

4.7y - 2.5y - 12.4 = 1.9

Now combine like terms:

4.7y - 2.5y = 2.2y

So the equation becomes:

2.2y - 12.4 = 1.9

Now, add 12.4 to both sides to isolate y:

2.2y = 14.3

Finally, divide by 2.2 to solve for y:

y = 14.3 / 2.2
y ≈ 6.5

Therefore, the solution to the equation is y ≈ 6.5.