Question 1042585
rewrite as 5x^2-9x=1
factor out a 5 a
5[x^2-(9/5)x]=1
divide by 5
(x-(9/5)x=1/5
now complete the square
x-(9/5)x+81/100=(1/5)+(81/100); divide the middle term by 2, to make 9/10, then square it and add to both sides.
(x-(9/10)^2=(101/100), common denominator of 100.
x=(9/10)+/-sqrt(101)/10, since square root of 100 is 10
numerically, this is 0.9+/-1, or very close to it.  Answer should be 1.9 and -0.1.
{{{graph(300,300,-5,5,-10,10,5x^2-9x-1)}}}
Quadratic formula:
x=(1/10)(9+/-sqrt(81+20)) and that is (9/10)+/-sqrt (101/100)