For this case we must find an expression to find 40% of 25. So, we make a rule of three:
25 -----------> 100%
x -------------> 40%
Where "x" represents the amount that determines 40% of 25.
40% of 25 is 10. And an expression to find it is:
Answer:
Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer: c and e
explanation: put the equation in the graphing calculator and look at the graph and table the answer will show
The question as presented is incomplete, here is the complete question with the multiple choice:
The sequence a1 = 6, an = 3an − 1 can also be
written as:
1) an = 6 ⋅ 3^n
2) an = 6 ⋅ 3^(n + 1)
3) an = 2 ⋅ 3^n
4) an = 2 ⋅ 3^(n + 1)
The correct choice is option 3) an = 2⋅3^n.
If we look at the initial sequence an = 3⋅an-1, and
a1 = 3⋅a0 = 6
a0 = 6/3
a0 = 2
We can now look at the sequence.
a0 = 2
a1 = 6
a2 = 18
a3 = 54
etc...
A common factor in each of those numbers is 2, so we can rewrite the sequence by factoring out 2.
a0 = 2⋅1
a1 = 2⋅3
a2 = 2⋅9
a3 = 2⋅27
The numbers being multiplied by 2 are all factors of 3. So we can rewrite the sequence again as:
a0 = 2⋅3^0
a1 = 2⋅3^1
a2 = 2⋅3^2
a3 = 2⋅3^3
This sequence can now be rewritten as an = 2⋅3^n.
