Question 1204773
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We can use a tool like Desmos to check to see if two conic section equations are the same or not.
<a href="https://www.desmos.com/calculator/ghu0cz1peh">https://www.desmos.com/calculator/ghu0cz1peh</a>


In the 1st box is the original equation.
The 2nd box is the answer your textbook claims (unfortunately the wrong answer).
The 3rd box is the correct answer <font color=red size=4>x^2 - 36y^2 + 8x - 108y - 74 = 0</font> where the 90 should be 74.



Curve1 and curve2 do not overlap, so we don't have a match.
But curve1 and curve3 do overlap. 
Click on the 3rd graph to turn it on and off. 
Repeatedly do this to have the curve blink different colors to help see the overlap.
Turn off curve2 if necessary.
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