Answer:
This is an RTD question. Here is a table based on the given information:
up/down . . . .rate . . . .time . . . .distance
upstream . . . . r-4 . . . . T . . . . 7
downstream . . . . r+4 . . . . T . . . .15
Now, rate x time = distance, so
time = distance / rate.
solve each for T and we get
T = (7/(r-4))
T = (15/(r+4))
set the times equal and we get
7%2F%28r-4%29+=+15%2F%28r%2B4%29
cross multiply to get
7r+%2B+28+=+15r+-+60
subtract 7r to get
28+=+8r+-+60
add 60 to both sides to get
88+=+8r
divide by 8 to get
r+=+8tep
Answer:
x = 10
Step-by-step explanation:
To isolate the variable (x) you would first write out x - 3 = 7. Now to make x on its own we have to get rid of the -3 so to do that we would add the reciprocal of -3 (or the opposite) which is +3. x - 3 + 3 = 7 + 3 or x = 10.
Answer: C. -2 = 2 + 5a - 2 - 6a
-2 - 2 + 2 = 5a - 6a
-2 = - a
2 = a
Answer: -4
Step-by-step explanation:
Answer:
49
Step-by-step explanation:
49
