The second one would be the answer. You want to plug in for this question. You can divide over the five leaving you with (x-2)^2 =25. Since you are squaring this answer, you want to get either 5 or negative five. Both -3 and 7 will do that.
(x-2) ^2 = 125/5, from formula (a-b)^2= a^2 - 2ab+ b^2 the equation becomes x^2 - 4x+4= 25 x^2-4x-21= 0 x^2 -7x+3x-21=0 x(x-7)+3(x-7)= 0 (x+3) (x-7)= 0 so either x+3=0 or x-7=0 x can have values x= -3, 7
