Let's solve the given equations using quadratic formula .
Quadratic formula :
x=−b±√b2−4ac2a
1) x2−6x+9=0
Using formula, we have
x=−(−6)±√(−6)2−4(1)(9)2(1)
⇒x=6±√36−362
⇒x=6±√02
⇒x=3
2) x2−2x+1=0
Using formula, we have
x=−(−2)±√(−2)2−4(1)(1)2(1)
⇒x=2±√4−42
⇒x=2±√02
⇒x=1
3) x2−4x+4=0
Using formula, we have
x=−(−4)±√(−4)2−4(1)(4)2(1)
⇒x=4±√16−162
⇒x=4±√02
⇒x=2
4) x2+2x+1=0
Using formula, we have
x=−(2)±√(2)2−4(1)(1)2(1)
⇒x=−2±√4−42
⇒x=−2±√02
⇒x=−1