Mark brainliest pls :)
a.
38<14+0.05x
24<0.05x
x>480
b. When the number of calls per month is greater than 480, then Plan 1 is more economical. Example: If the number of calls is greater than 480 say 500, then charges in plan 2 will be $39, but Plan 1 is more economical and charges will be $38.
As far as I understand A)
Answer:
option D
Step-by-step explanation:
take 39 degree as reference angle
using cos rule
cos 39 = adjacent / hypotenuse
0.77 = x / 7
x = 7*0.77
x = 5.39
x = 5.4
Answer:
B) Independent; the 1st marble selection will not affect the 2nd marble selection.
Step-by-step explanation:
When finding the probability of events in mathematics, we have both independent and dependent events.
Independent events are events that occur when the results of selection of the first events does not affect the results or outcomes of the second events.
Dependent events are the opposite of Independent events. They are events that occur when the results or outcomes obtained from the second events is affected by the results or outcomes from the selection of the first events.
From the question, we can see that the first event is she picked one marble from the bag. The second event is she replaced the marble before picking another marble. By doing this, the total number of possible outcomes for the probabilities of both events remains the same and they are unaffected.
Therefore, we can say that the two events are Independent because the 1st marble selection will not affect the 2nd marble selection.
Answer:
x = 2 sqrt(3) or x = -2 sqrt(3) or x = sqrt(3) or x = -sqrt(3)
Step-by-step explanation:
Solve for x:
-8 + x^2 + (x^2 - 8)^2 = 20
Expand out terms of the left hand side:
x^4 - 15 x^2 + 56 = 20
Subtract 20 from both sides:
x^4 - 15 x^2 + 36 = 0
Substitute y = x^2:
y^2 - 15 y + 36 = 0
The left hand side factors into a product with two terms:
(y - 12) (y - 3) = 0
Split into two equations:
y - 12 = 0 or y - 3 = 0
Add 12 to both sides:
y = 12 or y - 3 = 0
Substitute back for y = x^2:
x^2 = 12 or y - 3 = 0
Take the square root of both sides:
x = 2 sqrt(3) or x = -2 sqrt(3) or y - 3 = 0
Add 3 to both sides:
x = 2 sqrt(3) or x = -2 sqrt(3) or y = 3
Substitute back for y = x^2:
x = 2 sqrt(3) or x = -2 sqrt(3) or x^2 = 3
Take the square root of both sides:
Answer: x = 2 sqrt(3) or x = -2 sqrt(3) or x = sqrt(3) or x = -sqrt(3)
