The number of positive roots is the number of changes of signs there are, then decrease by 2 each time and stop when you get to 1 or 0
negative roots, sub every x with -x and reevaluate, count change of signs
decrease by 2 each time and stop when you get to 1 or 0
y=+2x⁵-x⁴-2x³+4x²+x-2
+,-,-,+,+,-
1 2 3
3 or 1 positive roots
replace x with -x ( baically flip all signs of odd powerd numbers)
y=-2x⁵-x⁴+2x³+4x²-x-2
-,-,+,+,-,-
1 2
2 or 0 negative roots
3 or 1 positive roots
2 or 0 negative roots
2nd option is answer
Answer:
750 grams of 60% alloy
Step-by-step explanation:
Define x = amount of 60% alloy and y = amount of 20% alloy
Equating the amounts of gold:
0.6x+0.2y = 1000(0.5)
Since there must be 1000 grams total:
x+y = 1000
Writing the 2 resulting equations together:
0.6x + 0.2y = 500
x + y = 1000
Multiply the first equation by 5:
3x + y = 2500
x + y = 1000
Subtracting the 2nd equation from the 1st:
2x = 1500
x = 750
Answer: 750 grams of 60% alloy
A farm had 480 acres more wheat than corn. Let use "W" to represent the Wheat and let use "C" to represent the corn. Hence, we have below:
W=C+480
The farmers collected 80% of the wheat and 25% of the corn and the area of the wheat is 300 acres less than the area of the corn:
W-0.8W=C-0.25C+300
0.2W=0.75C+300
We have two equations, two unknowns:
0.2(C+480)=0.75C+300
0.2C+96=0.75C+300
0.55C=294
C=534.55
Answer:
6 eggs
Step-by-step explanation:
48 (total eggs) divided by 8 (total hens) = 6 eggs for each hen
