∑ ( from n = 1 to n =5 ) 3 · ( -2 ) ^( n -1 )
a 1 = 3 · ( -2 ) ^0 = 3
a 2 = 3 · ( - 2 ) = - 6
a 3 = 3 · 4 = 12
a 4 = 3 · ( - 8 ) = - 24
a 5 = 3 · 16 = 48
3 - 6 + 12 - 24 + 48 = 33
Answer: C ) 33
Answer:
327 children and 318 adults
Step-by-step explanation:
The x be the amount of children and y be the amount of adults that were at the swimming pool. We can use this to set up a system of equations:
x+y=645
1.75x+2.50y=1367.25
Move y to the other side in the first equation to isolate x and solve the system using substitution:
x=645-y
1.75(645-y)+2.50y=1367.25
Distribute
1128.75-1.75y+2.50y=1367.25
1128.75+0.75y=1367.25
Subtract 1128.75 from both sides
0.75y=238.5
Divide both sides by 0.75
y=318
x=645-y
x=645-318
x=327
327 children and 318 adults swam at the pool that day
Phil ran 2 7/8 miles more than micheal
