2y²(6y-1)+3y(y-4y²)

To simplify the expression 2y²(6y-1) + 3y(y-4y²), we'll start by expanding the terms inside each bracket:

2y²(6y-1) = 12y³ - 2y² 3y(y-4y²) = 3y² - 12y³

Now, we can combine like-terms:

12y³ - 2y² + 3y² - 12y³

Combining the y³ terms, we have:

12y³ - 12y³

Which simplifies to zero:

0 - 2y² + 3y²

Finally, combining the y² terms, we get:

y²

Therefore, the simplified expression is y².