A(n)=4+4(n-1)
a(n)=4+4n-4
a(n)=4n
76=4n
n=19
The sum of any arithmetic sequence (series are infinite) is:
(a+a(n))(n/2)
The average of the first and last terms times the number of terms, in this case we found that n=19 so:
19(4+76)/2=760
480=60(v+s)
480=60v+60s
8=v+s
s=8-v...
480=80(v-s) using s from above we get:
480=80(v-(8-v))
6=v-8+v
6=2v-8
2v=14
v=7, and since s=8-v, s=1
So the rate of the team is 7m/s while the rate of the stream is 1m/s
Step-by-step explanation:
3cm on map = 45 km
1 cm on map = Xkm
Xkm = 45 / 3
Xkm = 15km
Therefore scale = 1:15000
20% is alcohol and 80% is water hope this helped
How do you evaluate: To evaluate an algebraic expression, you have to substitute a number for each variable and perform the arithmetic operations. In the example above, the variable x is equal to 6 since 6 + 6 = 12. If we know the value of our variables, we can replace the variables with their values and then evaluate the expression.
