The answer is -7
2x-3(x+4)=-5
Multiply by -3
2x-3x-12=-5
Collect like terms
-x-12=-5
Move constant to the right to change its sign
-x=-5+12
Add
-x=7
Change the signs
x=-7
Answer:
21 and 22
Step-by-step explanation:
Let's work backward from that 81%: x/25 = 0.81 yields x = 20.25. Nominally, 20.25 / 25 = 0.81, but x must be an integer. Let's round 20.25 off to 20.
Thus, if Kalsom got 81%, it was a result of his having done 20 questions correctly.
81% corresponds to 20 questions correct;
82% to 20.5 questions correct, or, rounding up, to 21 questions correct;
83% to 20.75, or 21;
84% to 21 questions correct; this is the only result that makes sense (whole number of questions answered correctly)
85% to 21.25;
86% to 21.5;
87% to 21.75;
88% to 22 questions correct (this makes sense, unlike the last three)
89% to 22.25;
90% to 22.5;
91% to 22.75;
Assuming that the number of questions correct MUST be integer, then the possible number correct are 21 and 22, corresponding to 84% and 88% respectively.
Answer:
Step-by-step explanation:
This is a binomial probability distribution because there are only 2 possible outcomes. It is either a randomly selected student grabs a packet before being seated or the student sits first before grabbing a packet. The probability of success, p in this scenario would be that a randomly selected student sits first before grabbing a packet. Therefore,
p = 1 - 0.81 = 0.91
n = 9 students
x = number of success = 3
The probability that exactly two students sit first before grabbing a packet, P(x = 2) would be determined from the binomial probability distribution calculator. Therefore,
P(x = 2) = 0.297
