Evaluate 3x^3y-2/5x^-2y^3 for x=2 and y=3 32/405 160/81 2/5

Let's try to simplify that a bit. Rewriting it in its current form it looks like this:

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We could split it up and deal with one problem at a time if we do this:

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The rule with like bases and division of the exponents is that we subtract the lower exponent from the upper so that would be

which gives us new exponents of

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We rewrite to make that negative exponent a positive by putting it under a 1, so the whole problem with no negatives looks like this now:

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If x = 2 and y = 3, we sub in accordingly:

which simplifies to , the first choice above.

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.