Answer:
Option 3. -8
Step-by-step explanation:
we have
[tex]x^{2} -10x+8=0[/tex]
Group terms that contain the same variable, and move the constant to the opposite side of the equation
[tex]x^{2} -10x=-8[/tex]
Complete the square. Remember to balance the equation by adding the same constants to each side
[tex]x^{2} -10x+25=-8+25[/tex] ----> the isolated constant right side is -8
[tex]x^{2} -10x+25=17[/tex]
Rewrite as perfect squares
[tex](x-5)^{2}=17[/tex]
Square root both sides
[tex]x-5=(+/-)\sqrt{17}[/tex]
[tex]x=5(+/-)\sqrt{17}[/tex]
