Answer:
4 - ( 3x - 8 ) = 21
break the bracket first ,it gives : 4 - 3x + 8 = 21
12 - 3x = 21
- 3x = 21 - 12
- 3x = 9
-x = 9/3
-x = 3
X = - 3
[ check if the answer is correct, put -3 instead of X in the above equation ! we get 4 - { 3(-3) - 8 } = 21
4 - { - 9 - 8 } = 21
4 - { - 17 } = 21
break the bracket, minus and minus will multiply and will become plus , so we have 4 + 17 = 21 , hence 21 = 21 ! therefore X = -3
Answer:
B
Step-by-step explanation:
Its the only odd number
Answer:
The probability is 0.9211
Step-by-step explanation:
Let's call K the event that the student know the answer, G the event that the student guess the answer and C the event that the answer is correct.
So, the probability P(K/C) that a student knows the answer to a question, given that she answered it correctly is:
P(K/C)=P(K∩C)/P(C)
Where P(C) = P(K∩C) + P(G∩C)
Then, the probability P(K∩C) that the student know the answer and it is correct is:
P(K∩C) = 0.7
On the other hand, the probability P(G∩C) that the student guess the answer and it is correct is:
P(G∩C) = 0.3*0.2 = 0.06
Because, 0.3 is the probability that the student guess the answer and 0.2 is the probability that the answer is correct given that the student guess the answer.
Therefore, The probability P(C) that the answer is correct is:
P(C) = 0.7 + 0.06 = 0.76
Finally, P(K/C) is:
P(K/C) = 0.7/0.76 = 0.9211
9 2/3 - 2 8/10 = 16 13/15
Answer:
y = 1/2
Step-by-step explanation:
<u>Step 1: Solve for y</u>
2y + 3 = 4y + 2
2y + 3 - 2 - 2y = 4y + 2 - 2 - 2y
1 / 2 = 2y / 2
1/2 = y
Answer: y = 1/2
