Please help with math?

A biologist found a system of equations to help her calculate the growth of bacteria. The functions she found y=2x^2-21 & y=9x−3

Part A – Explain how would she find the answer to her system of equations without using graphing technology.
Part B- Explain how to solve using graphing technology. How do you know the where the results of the system are?

1 Answer
Jul 11, 2018

I tried this:


I interpreted the question in the way that the two equations represent the growth of two types of bacteria (A ad B) where the first grows in a quadratic/parabolic way while the second in a linear way.
Probably the researcher wants to know at what instant in time (#x#) the two colonies have the same number #y# of elements (bacteria):

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Graphically you can "see" the solution by checking where the two curves cross each other.