# Algebra: 8th Grade; Equation Check

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1) A private airplane leaves an airport and flies due south at 192 km/h. Two hours later a jet leaves at the same airport and flies due south at 960 km/h. When will the jet overtake the plane?
t = time
Equation:
192(t+3) = 960

2)An airplane flew for 4 hours with a 20-km/h tail wind. The return flight against the same wind took 5 hours. Find the speed of the plane in still air.
r = rate in which the plane is moving
Equation:
4(r+20 = 5(r-20)

3) It takes a passenger train 2 hours less time than it takes a reight train to make the trip from Central City to Clear Creek. The passenger train averages 96 km/h while the freight train averages 63 km/h. How far is it from Central City to Clear Creek?
On this one, I don't know.

• Algebra: 8th Grade; Equation Check - ,

3) freight train's time = D/63
= D/96 + 2

D/63 - D/96 = 33 D /6048 = 2

D = 12096/33 = 366.55 miles

• Algebra: 8th Grade (#1) - ,

1) You had the wrong equation on the first one. It should be
192(t+3) = 960t, where t is the time the jet plane leaves.

2) Your equation is ok here, if r is the speed in still air

• Algebra: 8th Grade; Equation Check - ,

I don't get number 3
and I am sorry, but I made a typo.
The freight train travels at 64 km/h.

If the passenger train takes 2 hours LESS time than it takes the Freight train to make the trip from Central Park to Clear Creek.
how is the equation:
D/63 = D/96 + 2
make sense.
shouldn't it be d/96 = d/64 - 2 ??

• Algebra: 8th Grade; Equation Check - ,

With 64 instead of 63 you will get an integer answer, 12096/32 = 378. Do the math the same way.

d/96 = d/64 - 2 is basically what I wrote, but rearranged and with your corrected 64 in place of the 63.

• Algebra: 8th Grade; Equation Check - ,

how do i slove this problem? y<-3

• Algebra: 8th Grade; Equation Check - ,

what is 4w-9(6-5w)=44;w=3

• Algebra: 8th Grade; Equation Check - ,

1/2 times Y plus 3 = 15 What is the value of the Y