困難factorization

x^2 - 2x + 15 = 0
Unfactorizable

Quadratic Formula:
x = (2 +/- #( 4 - 4(1)(15) ) ) / (2) #()=square root
x = (2 +/- #(4 - 60) ) / 2
x = (2 +/- #(-56) ) / 2
x = (2 +/- #(56)i ) / 2
x = 1 +/- (#(56)i / 2)

You should be able to check solution to verify whether or not the solution is right.

please solve this：x^2－2x+15=0
Sol
x^2－2x+15=0
D=(－2)^2-4*1*15=-56
x=(2+/-sqrt(-56))/2=1+/-isqrt(14)
So
x^2－2x+15=(x－1+isqrt(14))(x－1-isqrt(14))

　∆
=(-2)^2-4*1*15
=-56
∴It has no solution.