<h3>Answers:</h3>
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Explanation:
x = number of seconds that elapse
y = altitude (aka height) of the plane
The equation for plane A is
y = 20.25x+2652
because it starts off at 2652 ft in the air, and then adds on 20.25 feet per second which is what the 20.25x describes
The equation for plane B is
y = 75.5x
The y intercept is zero because plane B starts on the ground, aka height 0.
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The system of equations is
![\begin{cases}y = 20.25x+2652\\y = 75.5x\end{cases}](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7Dy%20%3D%2020.25x%2B2652%5C%5Cy%20%3D%2075.5x%5Cend%7Bcases%7D)
If we want to know when they'll reach the same height (y), then we can set the two right hand sides equal to each other and solve for x.
75.5x = 20.25x+2652
75.5x-20.25x = 2652
55.25x = 2652
x = (2652)/(55.25)
x = 48
The two planes reach the same altitude at exactly <u>48 seconds</u>
That altitude is <u>3624 feet</u> because
- y = 20.25*x + 2652 = 20.25*48+2652 = 3624
- y = 75.5*x = 75.5*48 = 3624
Notice I plugged x = 48 into each equation and I got the same y value of y = 3624. This helps confirm the answers.