Transcript College Placement Test What is the value of the expression 2x2 + 3xy – 4y2 when x = 2 and y =

College Placement Test
What is the value of the expression 2x2 + 3xy – 4y2
when x = 2 and y = - 4?
A. -80
B. 80
C. -32
D. 32
Substitute 2 for x and -4
for y and solve using the
proper order of
operations.
A. -80
Explanation:
2 x  3 xy  4 y
2
2
Exponents first…
2(2)  3(2)( 4 )  4( 4 )
Multiply left to
right…
2(4)  3(2)( 4)  4(16)
Add or subtract left
to right…
2
2
8  (24)  64
 16  64
 80