Answer:
x=5 twice
Step-by-step explanation:
x^2-10x+25=0
multiply the coefficient of x^2 and the last term
1X25=25
find two numbers you can multiply to get 25 and add to get -10
-5 + (-5)=-10 the middle term
replace -10x with -5x -5x and solve the equation
x^2-5x-5x+25=0
factorise by grouping
x(x-5)-5(x-5)=0
(x-5)(x-5)=0
Either x-5=0,x=5 or x-5=0,x=5
Therefore x=5 twice.