Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream = 
time downstream = 
the ferry trip upstream takes twice as long as its return trip downstream
= 
divide both sides by d
= 
cross multiply


Add 2x on both sideds

subtract 15 from both sides and divide by 3

x=5
Speed of river's current = 5 mph
Answer:
24 ft sq.
Step-by-step explanation:
formula for area of triangle is: bh/2
8(6)/2 = area
48/2 = area
24 = area
Answer:
5 g
Step-by-step explanation:
Answer:
1) m = h - w/8
Subtract h from both sides.
m - h = -w/8
Subtract m from both sides.
-h = -m - w/8
Divide all terms by -1.
h = m + w/8.
2) m = h - w/8
Get rid of the denominator 8 by multiplying 8/1 to all terms.
8m = 8h - w
Add w on both sides and subtract 8m from both sides.
w = 8h - 8m
3) w = x + y/z
Get rid of the denominator z by multiplying it to all terms.
wz = xz + y
Subtract xz from both sides of the equation.
wz - xz = y OR y = wz - xz
4) w = x + y/z
Subtract x from both sides.
w - x = y/z
Get rid of the denominator by multiplying it to all terms.
wz - xz = y
Now factor the expression wz - xz.
z(w - x) = y
Divide both sides by w - x.
z = y / w - x
This is read as z equals to y divided by w minus x.
5) The area of a triangle is A = 1/2bh
First, get rid of the denominator by multiplying both sides by 2.
2A = bh
To find b, divide both sides by h.
2A/h = b
6) P = kt/v
Multiply both sides by v.
Pv = kt
Divide both sides by t.
Pv/t = k OR k = Pv/t.
Step-by-step explanation:
To find A' they used the rule of multiplication, which is:
the derivative of a product of two terms is the first term times the derivative of the second term plus the second term times the derivative of the first.
To find b' they just isolated b'