Answer:

Step-by-step explanation:
The systems of equations are
Let us assume the rate of the current be c
Now actual speed against the current is (15 - c)
And, the actual speed with the current is (15 + c)
Here we applied the time formula i.e. distance by speed
Also the upstream time - downstream time = 4
Now the equations are

Answer:
b = 1530
Step-by-step explanation:
1/17 b = 90
(17)1/17b = 90 × 17
b = 1530
Answer:
Step-by-step explanation:
2-(-1\8)±-7\4 then
2 plus 1\8 plus -7\4
2 plus 1\8 plus -14\8
2 -13\8
2= 16/8
3\8?
Answer:
$12.75
Step-by-step explanation:
Skubic Family-
22.75 = 5.25 + 7x
17.5 = 7x
2.5 = x
Therefore the cost for each person is equal to $2.5
Shaw Family-
2.5(3) + 5.25
7.5 + 5.25 = $12.75