Answer:
The speed in still water is 5 miles per hour.
Step-by-step explanation:
distance with current = 90 miles
distance against current = 10 miles
speed in still water = s
speed of current = 4 mph
speed with current = s + 4
speed against current = s - 4
time = t
speed = distance/time
distance = speed * time
With current:
90 = (s + 4) * t
Against the current:
10 = (s - 4) * t
We have a system of equations:
90 = (s + 4) * t
10 = (s - 4) * t
90 = ts + 4t
10 = ts - 4t
Subtract the second equation from the first equation.
80 = 8t
10 = t
t = 10
10 = t(s - 4)
10 = 10(s - 4)
1 = s - 4
s = 5
Answer: The speed in still water is 5 miles per hour.
226.981 I think Because you have to multiply 6.1*6.1*6.1
-2(m + 4) = 40
The first step is to use the distributive property to clear the parenthesis
-2 * m + -2* 4 = 40
-2m - 8 = 40
next, to isolate the variable, add 8 to both sides
-2m - 8 + 8 = 40 + 8
-2m = 48
the last step is to get rid of the multiplication by -2 we will divide by -2
(-2m)/-2 = 48/-2
m = -24
Answer:
98 and 7/25
Step-by-step explanation:
91x2/25+91=total price
182/25+91=total
7 and 7/25+91=total
total=98 and 7/25
