2y²(6y-1)+3y(y-4y²)

To simplify the expression 2y²(6y-1)+3y(y-4y²), we will first distribute the coefficients.

Starting with the first term, 2y² * (6y-1), we get: = 12y³ - 2y²

Next, for the second term, 3y * (y-4y²), we have: = 3y² - 12y³

Now, we can combine like terms by adding our results: = (12y³ - 2y²) + (3y² - 12y³)

Combining the terms: = 12y³ - 2y² + 3y² - 12y³

Now, we can simplify this further by grouping the like terms: = (12y³ - 12y³) - 2y² + 3y²

Simplifying again: = -2y² + 3y²

Finally, combining the like terms: = y²