Answer:
20 mph
Step-by-step explanation:
time = distance / speed
speed up stream = s - 4
speed down stream = s + 4
time up = time down
8 / (s - 4) = 12 / (s + 4)
cross multiply
8s + 32 = 12s - 48
subtract 8v from both sides
32 = 4s - 48
add 48 to both sides
80 = 4s
Divide both sides by 4
20 = s
20mph
The factors are..
1,3
Hence we see that:
x2+4x+3= (x+3)(x+1)
Therefore the factors are
x= 3 or 1
1 1/2
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