How do you solve the equation by graphing x^2 - 18x + 81 = 0?

1 Answer
Ryan
Jun 6, 2017

Factorise and sketch!

Explanation:

If x^2 -18x+81=0, then it follows that (x-9)^2=0 through factorisation. Therefore x can only equal 9 for only that value satisfies the above equation.

To sketch this, you know that (9,0) is your one and only x-intercept, and that your graph will turn at that coordinate too. Your y-intercept, reading from your original equation is at (0, 81).

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