8x*3y*(-5y)-7x²*(-4y)

To simplify the expression \( 8x \cdot 3y \cdot (-5y) - 7x^2 \cdot (-4y) \), follow these steps:

1. Distribute the terms:

   • For the first term: \[ 8x \cdot 3y \cdot (-5y) = 8 \cdot 3 \cdot (-5) \cdot x \cdot y \cdot y = -120xy^2 \]
   • For the second term: \[ -7x^2 \cdot (-4y) = 7 \cdot 4 \cdot x^2 \cdot y = 28x^2y \]

2. Combine the simplified terms: Now, we can combine both parts: \[ -120xy^2 + 28x^2y \]

Thus, the simplified form of the expression is: \[ 28x^2y - 120xy^2 \]