Gr. 10 Math

Evaluate each expression for the given value(s) of the variable(s).

2x^2 - 3xy + 4y^2 for x=2, y=-1

My Answer:
(2(2^2)) - (3*2*-1) + (4(-1^2)) = 10

Text Book Answer: 18

Please help. Am I doing something wrong? I redid the expression 3 times and still got 10. But why textbook say it's 18?

Thank you.

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asked by John
  1. 2x^2 - 3xy + 4y^2 for x=2, y=-1

    My Answer:
    (2(2^2)) - (3*2*-1) + (4(-1^2)) = 10

    8-(-6)+4(1)=14+4=18

    The text book is correct.

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    posted by Dr Russ

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