Answer:
1/5? 0.2?
Step-by-step explanation:
Answer:
28.
a. false
b. true
c. false
d. false
2. 8.4 X 2.3 X 2.09 = 40.3788
3. $10.04 - $13.47
4. Your friend would be incorrect because their decimal is in the wrong place. Take the decimals out of it and think about it. Can 1 times 2 equal anything near 31? no, so it's not reasonable that your friend could multiply 1.2 X 2.6 and get anything near 31.2
5. It is more reasonable to say between 5 and 6 because even when you round both of the numbers up (3 X 2), you still only get 6.
Step-by-step explanation:
ill put it in the comments so I can get this to you faster.
Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many combination of random samples of 4 students can be selected?
4 from a set of 12. So

495 combinations of 4 students can be selected.
Answer:
case a)
----> open up
case b)
----> open down
case c)
----> open left
case d)
----> open right
Step-by-step explanation:
we know that
1) The general equation of a vertical parabola is equal to

where
a is a coefficient
(h,k) is the vertex
If a>0 ----> the parabola open upward and the vertex is a minimum
If a<0 ----> the parabola open downward and the vertex is a maximum
2) The general equation of a horizontal parabola is equal to

where
a is a coefficient
(h,k) is the vertex
If a>0 ----> the parabola open to the right
If a<0 ----> the parabola open to the left
Verify each case
case a) we have

so


so

therefore
The parabola open up
case b) we have

so



therefore
The parabola open down
case c) we have

so



therefore
The parabola open to the left
case d) we have

so



therefore
The parabola open to the right