Answer:
x = -3 or x = 5
Step-by-step explanation:
Solve: x^2 -2x = 15
x^2 - 2x - 15 = 0
Use the Diamond method of factoring
-15 = 3* -5 and 3 - 5 = -2 so...
x^2 - 2x - 15 = x^2 - 5x + 3x - 15
x^2 - 2x - 15 = x *(x - 5) + 3*(x - 5)
x^2 - 2x - 15 = (x + 3)*(x - 5)
x^2 - 2x - 15 = (x + 3)*(x - 5) = 0
solve (x + 3 ) = 0 and (x - 5) = 0
x = -3 or x = 5
Answer:
a) 1/2
b) 1/n
c) 1/4
Step-by-step explanation:
a) For each permutation, either 1 precedes 2 or 2 precedes 1. For each permutation in which 1 precedes 2, we can swap 1 and 2 to obtain a permutation in which 2 preceds 1. Thus, half of the total permutations will involve in 1 preceding 2, hence, the probability for a permutation having 1 before 2 is 1/2.
c) If 2 is at the start of the permutation, then it is impossible for 1 to be before 2. If that is not the case, then 1 has a probability of 1/n-1 to be exactly in the position before 2. We can divide in 2 cases using the theorem of total probability,
P( 1 immediately preceds 2) = P (1 immediately precedes 2 | 2 is at position 1) * P(2 is at position 1) + P(1 immediately precedes 2 | 2 is not at position 1) * P(2 is not at position 1) = 0 * 1/n + (1/n-1)*(n-1/n) = 1/n.
d) We can divide the total of permutations in 4 different groups with equal cardinality:
- Those in which n precedes 1 and n-1 precedes 2
- those in which n precedes 1 and 2 precedes n-1
- those in which 1 precedes n and n-1 precedes 2
- those in which 1 precedes n and 2 precedes n-1
All this groups have equal cardinality because we can obtain any element from one group from another by making a permutations between 1 and n and/or 2 and n-1.
This means that the total amount of favourable cases (elements of the first group) are a quarter of the total, hence, the probability of the event is 1/4.
Answer:
E
Step-by-step explanation:
x < -5.2
x > 5.2
How do I explain...?
Answer:
Adult: 50 tickets
Child: 34 tickets
Step-by-step explanation:
Let a be the amount of adult tickets
Let c be the amount of child tickets
Equation:
a + c = 84
14a + 9c = 1,006
Step 1: Multiply a + c = 84 with -9, to canceled c.
-9 (a + c = 84) → -9a - 9c = -756
14a + 9c = 1006 → 14a + 9c = 1006
Step 2: Combined the 2 equation together, and solved it.
-9a - 9c = -756
<u>14a + 9c = 1006</u>
<u> 5a</u> = <u>250</u>
5 5
a = 50
Step 3: Plug 50 into the one of the equation, and solved it.
a + c = 84 → 50 + c = 84
<u>-50 -50</u>
c = 34
Answer: Adult tickets (a) = 50 and Child tickets (c) = 34
To check the answer plug the two number into the equation ( Make sure to add 50 for a and 34 for c).
Answer:
60.3
Step-by-step explanation:
hope this helps