standard_description: Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.
problem_activity: Task
The first three steps of three visual patterns are shown below.
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Here are functions that define how many tiles are in step $n$, in no particular order: $$f(n)=3n^2$$ $$g(n)=n^2+4$$ $$h(n)=n^2-1$$
Decide which function defines which pattern.
One of these patterns has a step with $432$ tiles in it, one has a step with $195$ tiles in it, and one of these patterns has a step with $404$ tiles in it. Decide which is which, find the step that contains that number of tiles, and explain how you know.
Describe and justify the steps to solve this equation for $x$. $$ax^2+c=d$$


aligns: no