2y²(6y-1)+3y(y-4y²)

To simplify the expression 2y²(6y-1) + 3y(y-4y²), we need to apply the distributive property and combine like terms.

Let's start with the first term: 2y²(6y-1).

Applying the distributive property, we get: 2y² * 6y + 2y² * -1

Simplifying this further: 12y³ - 2y²

Now let's move on to the second term: 3y(y-4y²).

Applying the distributive property, we get: 3y * y + 3y * -4y²

Simplifying this further: 3y² - 12y³

Now we can combine the two simplified terms: (12y³ - 2y²) + (3y² - 12y³)

Combining like terms: 12y³ - 2y² + 3y² - 12y³

Simplifying this further: -9y³ + y²

So the simplified form of the expression 2y²(6y-1) + 3y(y-4y²) is -9y³ + y².