Count change of signs to tell positive roots
then replace x with -x and evaluate, then count change in sign for negative roots
initially
+, -, -, +, +, -
3 changes
3 or 1 positive roots
replacing x with -x
-,-,+,+,-,-
2 changes
2 or 0 negative roots
B is answer
Answer:
Number of high quality version downloads = 880
Step-by-step explanation:
Let,
x be the number of standard version songs downloaded
y be the number of high quality version songs downloaded
According to given statement,
x+y=1600 Eqn 1
2.8x+4.1y=5624 Eqn 2
Multiplying Eqn 1 by 2.8 to eliminate x
2.8(x+y=1600)
2.8x+2.8y=4480 Eqn 3
Subtracting Eqn 3 from Eqn 2
(2.8x+4.1y)-(2.8x+2.8y)=5624-4480
2.8x+4.1y-2.8x-2.8y=1144
1.3y=1144
Dividing both sides by 1.3

Hence,
Number of high quality version downloads = 880
<span>How much money was borrowed</span> $144/0.06 = $2,400.
Answer:
C. (1, 1, 2)
Step-by-step explanation:
Well plugging them in one by one.
x + y - z = 0
-1 + 2 - 4 = 0
no.... no it doesn't equal 0 so it isn't the solution
-1 + 0 - 2 = 0
nope it doesn't equal 0 so it's also not the solution
1 + 1 - 2 = 0
Yes! this could equal the solution so lets keep going down the line
3x - y + z = 4
(3*1) -1 + 2 = 4
Yes! this also is correct
I could keep talking and talking but yes, (1, 1, 2) is your answer
Hope this helps! <3