Lisa is using trial and improvement to find a solution to this equation:
x squared - 3x=1
what value of x should lisa try

Not sure about that but you can factor and solve
if you have xy=0 then x or/and y=0

so x^2-3x=1
subtract 1
x^2-3x-1=0
what 2 number multiply to get -1 and add to get -3
the numbers are aprox 3.15831 and -0.15831 so
(x+3.15831)(x-0.1831)=0
set them to zero
x+3.15831=0
subtract 3.15831 from both sides
x=-3.15831

x-0.1831=0
add 0.1831 to both sides
x=0.1831

so x=0.1831 or -3.15831