Answer:
x1 =2-5i*sqrt(2)
x2 =2+5i*sqrt(2)
Explanation:
-x^2 +4x-54=0 (quadratic equation)
a=-1, b=4, c=-54
x1=(-b+sqrt(b^2-4ac))/2a
x1=(-4+sqrt(4^2 - 4*(-1)(-54))/2*(-1)
x1=(-4+sqrt(16-216))/(-2)
x1 =(-4+sqrt(-200))/(-2)
x1 =(-4+sqrt(200i^2))/(-2) i^2=-1
x1 =(-4+sqrt(100*2*i^2))/(-2)
x1 =(-4+10i*sqrt(2))/(-2)
x1 =2-5i*sqrt(2)
x2 =(-b-sqrt(b^2-4ac))/2a
x2 =(-4-10i*sqrt(2))/(-2)
x2 =2+5i*sqrt(2)