Question 469000
x2-7x+9=0
*[invoke quadratic "x", 1, -7, 9 ]
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x2+8x+16=49
x2+8x-33=0
(x+11)(x-3)
x=-11 or 3
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(x-8)2=81
x2-16x+64=81
x2-16x-17=0
(x+1)(x-17)=0
x=-1 or 17..