First, we need to solve for the common ratio from the data given by using the equation.
a(n) = a(1) r^(n-1)
15 = -3 r^(2-1)
-5 = r
r = -5
Then, we can find the sum by the expression:
S(n) = a(1) ( 1 - r^n) / 1-r
S(8) = -3 (1 + 5^8) / 1+5
S(8) = -195313
Answer:
what this basicaly means is that we have to multiply 3 by every thing inside the parethese
3*2x=6x
3*1=3
6x+3
Hope This Helps!!!
4 > x
step by step explanation:
13 > 3x + 1
-1 -1
12 > 3x
/3 /3
4 > x
Let b and s be the velocity of the boat and stream respectively....
3(b-s)=27
b-s=9
b=9+s we will use this in the second equation....
2(b+s)=30
b+s=15, now use b found above in this to get:
9+s+s=15
2s+9=15
2s=6
s=3, and since from earlier b-s=9, b=9+s so
b=12
So the speed of the boat is 12mph and the stream is 3 mph
