How do you solve x210x+41=0?

1 Answer
May 11, 2017

Original question: Solve x210x+41=0

Since the equation cannot be easily factored, we must use the quadratic equation:
x=b±b24ac2a where a,b,c are from the standard form of a quadratic, f(x)=ax2+bx+c

In this question, a=1,b=10,c=41, which we can substitute into the quadratic equation and simplify:
x=(10)±(10)2414121
x=10±1001642
x=10±642

Since we cannot square root a negative number, we use i to denote the imaginary unit, i=1, and continue simplifying:
x=10±8i2
x=5±4i

Therefore, our solutions are:
x=5+4i,54i