Answer:
x=8 and y=3 (So, yes!)
Step-by-step explanation:
I will solve your system by substitution.
(You can also solve this system by elimination.)
−x+4y=4;−x+3y=1
Step: Solve −x+4y=4 for x:
−x+4y+−4y=4+−4y(Add -4y to both sides)
−x=−4y+4
-x/-1 = -4y+4/-1 (Divide both sides by -1)
x=4y−4
Step: Substitute 4y−4 for x in −x+3y=1:
−x+3y=1
−(4y−4)+3y=1
−y+4=1(Simplify both sides of the equation)
−y+4+−4=1+−4(Add -4 to both sides)
−y=−3
-y/-1 = -3/-1 (Divide both sides by -1)
y=3
Step: Substitute 3 for y in x=4y−4:
=4y−4
x=(4)(3)−4
x=8(Simplify both sides of the equation)
<u>Answer:</u>
x=8 and y=3
All you have to do is 3×5=15
then 8÷8=1 so 16 dollars
Answer: the rate of the jet in still air is 685 mph and the rate of the jetstream is 75 mph
Step-by-step explanation:
Let x represent the rate of the jet in still air.
Let y represent the rate of the jet jetstream.
Distance = speed × time
Flying against the jetstream, a jet travels 3050 miles in 5 hours. This means that the total speed of the jet would be (x - y) mph. Therefore,
3050 = 5(x - y)
3050/5 = x - y
x - y = 610 - - - - - - - - - - - - - -1
Flying with the jetstream, the same jet travels 3800 miles in 4 hours. This means that the total speed of the jet would be (x + y) mph. Therefore,
3800 = 4(x + y)
3800/5 = x + y
x + y = 760 - - - - - - - - - - - - - -2
Adding equation 1 to equation 2, it becomes
2x = 1370
x = 1370/2 = 685mph
Substituting x = 685 into equation 1, it becomes
685 - y = 610
y = 685 - 610 = 75mph
<h2>
Automobile must travel at 96 mph to pass the truck in 4 seconds.</h2>
Step-by-step explanation:
Length of automobile = 16 feet = 4.88 m
Length of truck = 28 feet = 8.53 m
Speed of truck = 30 mph = 48 km/h = 13.33 m/s
Time in which automobile to pass truck = 4 s
Distance traveled by truck in 4 seconds = 4 x 13.33 = 53.33 m
Distance which need to cover by automobile in 4 seconds to pass truck is the sum of length of automobile, length of truck and distance traveled by truck in 4 seconds.
Distance which need to cover by automobile in 4 seconds = 4.88 + 8.53 + 53.33
Distance which need to cover by automobile in 4 seconds = 66.74 m
Distance = Speed x Time
66.74 = Speed x 4
Speed = 16.69 m/s = 60 km/h = 96 mph
Automobile must travel at 96 mph to pass the truck in 4 seconds.
