To solve this equation for Y, we can follow these steps:

Subtract 3/10Y from both sides:

1,2 = 8/15Y + 0.78 - 3/10Y

Find a common denominator for Y terms:

1,2 = (8/15 - 3/10)Y + 0.78

Simplify the Y terms:

1,2 = (16/30 - 9/30)Y + 0.78
1,2 = 7/30Y + 0.78

Subtract 0.78 from both sides:

1,2 - 0.78 = 7/30Y

0.42 = 7/30Y

Multiply both sides by 30/7 to solve for Y:

Y = 0.42 * 30/7
Y = 1.8

Therefore, the solution to the equation is Y = 1.8.