1) (x+1)^2 - (x-1)^2 = (2x+1) - 4x^2
(x+1+x+1)(x+1-x+1) = 4x^2 + 4x +1 -4x^2 (4x^2 se simplifica cu -4x^2)
(2x+2)(2x) = 4x+1
4x^2 +2= 4x +1 /-4x
0x+2=1 /-2
0x = -1 => Solutia = multimea vida(acel O taiat de un segment)
2) x√7 + 3√5 = 3√7 + x√5
x√7 + 3√5 - x√5 = 3√7 /-3√5
x√7 + x√5 = 3√7-3√5
x(√7-√5) = 3(√7-√5) /: (√7-√5)
x = 3 => S=3
3) x√2+1 = x+√2 /-x
x√2 +1 -x = √2 /-1
x√2-x = √2-1
x(√2-1)= 1(√2-1) /:(√2-1)
x=1 => Sol.= 1
4) (3-√2)x + √2+3=0 /-√2-3
(3-√2)x = -√2-3
3x - √2x = -√2-3
3x- √2x= -3-√2
x(3-√2)=1)-3-√2
5) √6x + √20 = 0
√3•√2•x +√10•√2=0 / :√2
√2(√3x+√10)=0
√3x + √10 = 0 / -√10
√3x = -√10 /:√3
x= -√10supra√3(amplificam fractia cu √3)
x= -√30 supra 3
6) -2x+7=0 / -7
-2x = -7 /:(-2)
-x = -7/2/ • (-1)
x=7/2
