Posted by Leah on Monday, April 18, 2016 at 3:12am.
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)  Steve, Monday, April 18, 2016 at 5:47am
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)
= 82464
= 80