Question

If a plane can travel 490 miles per hour with the wind and 430 miles per hour against the​ wind, find the speed of the plane in still air.

Answer 1

460

Explanation:

Let b = base speed and w = wind power.

Here's what we know:

b + w = 490

b - w = 430

From here, we can use the elimination method. If we treat each variable and constant as columns, we do the following:

b + b = 2b

w - w = 0

490 + 430 = 920

Leaving us with:

2b = 920

Divide by 2:

2b / 2 = b

920 / 2 = 460

So b = 460 mph