Hi!
Tip #1: To multiply polynomials, consider the variables separate from the numbers.
So we are multiplying 2xyz * -4x²yz
Let's start by multiplying the variables.
xyz * x²yz
Tip #2: The exponents tell you how many of each variable there are. When multiplying variables, add the exponents. When a variable does not seem to have an exponent, that means there is an invisible exponent of 1! (x = )
xyz * x²yz = (x + x²)(y + y)(z + z) = x³y²z²
Now multiply the numbers! (just like normal)
2 * -4 = -8
Now combine the numbers with the variables once again.
-8x³y²z²
The answer for 2xyz * -4x²yz is -8x³y²z²
Hope this helps! :)