9514 1404 393
Answer:
x = 7
Step-by-step explanation:
The equation can be rewritten to ...
8x = 13n +4 . . . . for some integers x and n
x = (13n +4)/8
For x to be an integer, 13n must be an odd multiple of 4. Since 13 is an odd number, n=4 will do.
x = (13·4 +4)/8 = 56/8
x = 7
__
The graph shows a "trial and error" method of solution. Only values of x less than 13 need to be examined.
Answer: x = 9
Step-by-step explanation:
The sum of three interior angles of a triangle is 180°.
(9x - 3) + (6x) + 48° = 180°
9x - 3 + 6x + 48 = 180
15x + 45 = 180
15x = 135
x = 9
Answer:
Binomial
There is a 34.87% probability that you will encounter neither of the defective copies among the 10 you examine.
Step-by-step explanation:
For each copy of the document, there are only two possible outcomes. Either it is defective, or it is not. This means that we can solve this problem using the binomial probability distribution.
Binomial probability distribution:
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinatios of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
In this problem
Of the 20 copies, 2 are defective, so
.
What is the probability that you will encounter neither of the defective copies among the 10 you examine?
This is P(X = 0) when
.


There is a 34.87% probability that you will encounter neither of the defective copies among the 10 you examine.
Answer: it will take 25 months
Step-by-step explanation:
Let x represent the number of months that it will take for the cost of both plans to be the same.
Cell phone Plan A costs $70 per month and comes with a free $500 phone. This means that the total cost of x months with plan A would be
70 × x = $70x
Cell phone plan B costs 50 per month but does not come with a phone. If you buy the 500 phone and choose plan B, then the total cost of x months with plan B would be
500 + 50 × x = 500 + 50x
To determine the number of months until your cost is the same as Plan A's, we would equate both costs. It becomes
70x = 500 + 50x
70x - 50x = 500
20x = 500
x = 500/20 =25