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
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
What is the value of –2x2 + 4y if x = –2 and y = 3?
Simplify (2xsquare -3xy square)square
To find the value of the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4, we need to substitute the given values into the expression and simplify.
Step 1: Substitute the values of x and y into the expression.
2x^2 + 3xy - 4y^2 = 2(2)^2 + 3(2)(-4) - 4(-4)^2
Step 2: Simplify the exponents and compute the multiplication in each term.
2(4) + 3(2)(-4) - 4(16) = 8 - 24 - 64
Step 3: Perform the addition and subtraction.
8 - 24 - 64 = -16 - 64 = -80
Therefore, the value of the expression 2x^2 + 3xy - 4y^2 when x = 2 and y = -4 is -80.
I hope this explanation was helpful.