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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