Answer:
Step-by-step explanation:
Given that a fair coin is flipped twelve times.
It means the number of possible sequences of heads and tails would be:
2¹² = 4096
We can determine the number of ways that such a sequence could contain exactly 9 tails is the number of ways of choosing 9 out of 12, using the formula

Plug in n = 12 and r = 9


∵ 
∵ 

Thus, the probability will be:



Thus, the probability of the coin landing tails up exactly nine times will be:
180-96= 84
That means 8x+12=84
84-12=72
That means 8x=72
72÷8=9
therefore X=9
Answer:
5.09 × 10^-2
Step-by-step explanation:
You have to take the number go to the decimal and move it until you get to the first number and in this case, it is 5 put the decimal there. To write it you have to count the number of times you moved the decimal. when doing this it will always be a number times 10^ the number you moved the decimal.
Answer:
389.9 to 1 decimal place
If you need another explanation comment on this one
Answer:
x = -2 y= -8 and 8
Step-by-step explanation:
Since there is an equal number of y's, they cancel out when subtracting. You can put either equation on top. You will get same answer.
<u>To find x:</u>
<u>If you do (3x - 2y = 10) - (5x + 2y = 6),</u> you will get -2x=4. Divide both sides by -2, and get x = -2.
<u>If you do (5x + 2y = 6) - (3x - 2y = 10)</u>, you will get 2x=-4.Divide both sides by 2, and get x = -2.
<u>To find y:</u>
Substitute -2 for x in either equation. It doesn't matter.
<u>For 3(-2) - 2y = 10:</u>
3(-2) - 2y = 10 ––Multiply
-6 - 2y =10 ––Add 6 to both sides to get y alone
-2y = 16 ––Divide by -2
y = -8
<u>For 5x + 2y = 6:</u>
5(-2) + 2y = 6 ––Multiply
-10 + 2y = 6 ––Add 10 to both sides to get y alone
2y = 16 ––Divide by 2
y = 8