Bonsoir,
32. Il faut mettre au même dénominateur.
1)
V = [tex] \frac{1}{x+1} + \frac{2}{x-1} [/tex]
= [tex] \frac{(x-1)*1 + 2(x+1)}{(x+1)(x-1)} [/tex]
= [tex] \frac {x-1+2x+2}{x^2-1} [/tex]
= [tex] \frac {3x+1}{x^2-1}[/tex]
2)
I = [tex] \frac {5}{2x-1} +1 [/tex]
= [tex] \frac {5}{2x-1} + \frac{(2x-1)}{(2x-1)} [/tex]
= [tex] \frac {5+2x-1}{2x-1} [/tex]
= [tex] \frac {4+2x}{2x-1}[/tex]
3)
T = [tex] \frac{4}{x} + \frac {x-1}{3x+5} [/tex]
= [tex] \frac {4(3x+5)}{x(3x+5} + \frac {x(x-1)}{x(3x+5} [/tex]
= [tex] \frac {4(3x+5)+x(x-1)}{x(3x+5)} [/tex]
= [tex] \frac {12x+20+x^2-x}{3x^2+5x} [/tex]
= [tex] \frac {x^2+11x+20}{3x^2+5x}[/tex]
4)
E = [tex] \frac {x(x+1)}{(x+1)(1-5x)} + \frac {2(1-5x)}{(1-5x)(x+1)} [/tex]
= [tex] \frac {x(x+1)+2(1-5x)}{(1-5x)(x+1)} [/tex]
= [tex] \frac {x^2+x+2-10x}{x+1-5x^2-5x} [/tex]
= [tex] \frac {x^2-9x+2}{-4x+1-5x^2} [/tex]
= [tex] \frac {x^2-9x+2}{-5x^2-4x+1}[/tex]
