i don’t understand this
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You have to multiply whats outside the parenthesis with everything that is inside, so
[tex]x^{-3}y^0.(x^2-3x^5y^4)[/tex]
[tex]x^{-3}y^0.x^2-x^{-3}y^0.3x^5y^4[/tex]
Multiplication of same bases we sum the exponents
[tex]x^{-3+2}y^0-3x^{-3+5}y^{0+4}[/tex]
[tex]x^{-1}.1-3x^2y^4[/tex]
[tex]x^{-1}-3x^2y^4[/tex]
Alternative B.