Question

If (x − 2)^2=49, then x could be ?

Answer 1

(x-2)(x-2)
x^2 -2x -2x +4 =49 (-49 from both sides)
X^2-4x-45
(x+5)(x-9)
x=-5, x=9

Answer 2

`(x - 2)^2=49\\ \\ x^2-4x +4 -49=0\\ \\x^2-4x -45 = 0\\ \\\Delta = b^(2)-4ac = (-4)^(2)-4*1* (-45)= 16+180=196 \\ \\x_(1)=(-b-√(\Delta ))/(2a) =(4-√(196))/(2)=(4-14)/(2)=(-10)/(2)=-5 \\ \\x_(2)=(-b+√(\Delta ))/(2a) =(4+√(196))/(2)=(4+14)/(2)=(18)/(2)=9 \\ \\Answer : \ x=-5 \ or \ x= 9`