Math (Elementary Algebra)

posted by .

What is the value of the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4 ?
Please help this is for my accuplacer. If you could show your work explaining how you got the answer that would be awesome. Thank you in advance

  • Math (Elementary Algebra) -

    2x^2 + 3xy - 4y^2

    now substitute your values for every x and y:

    2(2^2) + 3(2)(-4) - 4(-4)^2
    = 2(4) - 24 - 4(16)
    = 8-24-64
    = -80

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math Algebra

    What is the value of expression 2x squared + 3xy-4y squared when x=2 and y=-4?
  2. 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?
  3. Algebra-Please check my answers

    Posted by Jessie on Monday, October 18, 2010 at 3:48pm. I think I figured it out-please check I'm really stuck on these problems- Simplify 6xy(3xy)^-2?
  4. algebra

    What is the value of the expression 2x to the 2nd power + 3xy -4y to the 2nd power when x = 2 and y = -4?
  5. 6th grade math

    Find the value fir each expression. Show your work. (13.28 - 7.8) divided by 4. I have the answer in the back of my book and when I try to work the problem out I keep getting the wrong answer. The answer is supposed to be 1.345 I can …
  6. Math

    what is the result when 2x^2+3xy-6 is subtracted from x^2-7xy+2?
  7. algebra

    what is the value of the expression 2xsquare+3xy-4ysquare when x=2 and y =4?
  8. Math!

    1) What is the value of 19 + 5a^4 + 3b^2 when a = 2 and b = -4?
  9. Algebra

    I need help explaining how to work this problem for my daughter... What is the value of n so that the expression x² + 11x + n is a perfect square trinomial?
  10. algebra

    What is the value of the expression below?

More Similar Questions