Answer:
x=50
Step-by-step explanation:
-0.2(x-20)=44-x
Distribute
-0.2x+4=44-x
Add x to each side
-.2x +4+x = 44-x+x
.8x+4 = 44
Subtract 4 from each side
.8x+4-4 = 44-4
.8x = 40
Divide each side by .8
.8x/.8 = 40/.8
x=50
Answer: The speed of red horse = 44 feet per second and the speed of black horse = 35.2 feet per second.
Step-by-step explanation:
Given: A red horse and a black horse raced on a 1-mile-long circular racetrack.
Time taken by red horse = 120 seconds
Time taken by black horse = 150 seconds
Speed = 
So, speed of red horse =
Since 1 mile = 5280 feet
Speed of red horse = 
Similarly,
Speed of black horse = 
Hence, the speed of red horse = 44 feet per second and the speed of black horse = 35.2 feet per second.
0.000044, because 10 to the negative fith is 0.00001, and 0.0001 times 4.4 is 0.000044