Don L. answered • 09/23/18

Tutor

5
(12)
Fifteen years teaching and tutoring basic math skills and algebra

Hi Ashlyn, let w represent the wind's speed and v represent the plane's speed. Use the equation, distance = rate times time to solve.

Equation with the wind:

1290 = (v + w) * 3

Equation against the wind:

1230 = (v - w) * 3

This gives us two equation, which can be solved using elimination.

1290 = (v + w) * 3

1230 = (v - w) * 3

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Divide both sides by 3:

430 = v + w

410 = v - w

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Add the two equation getting:

840 = 2v

Solve for v:

v = 420

Solve for w by replacing v in one of the two equations:

1290 = (420 + w) * 3

1290 = 1260 + 3w

Combine terms:

3w = 30

w = 10

The speed of the plane is 420 miles per hour and the speed of the wind is 10 miles per hour.

Questions?