Question

X^2-3x=7

Answer 1

start with
\[x^2-3x-7=0\] then use
\[\frac{-b\pm\sqrt{b^2-4ac}}{2a}\]with \[a=1,b=-3,c=-7\]

Answer 2

x^2-3x =7.. transfer -7 to the LHS and we obtain

x^2-3x+7=0.. now we can use quadratic equation where
a = 1,
b = -3, and
c = 7

the formular is x= [-b+/- sqrt(b^2 - 4ac)]/2a
x = [3+/- sqrt(9-28)]/2, so we have [3+sqrt-21]/2 or [3-sqrt-21]/2

that is [3+(sqrt21)i]/2 or [3-(sqrt21)i]/2

note that this are complex numbers and i represents sqrt of 1...