Réponse :
1)
2/x + 3/(x-1) = ( 2(x-1) + 3 ) /( x(x-1)) = (2x -2 +3) / ( x(x-1))
= (2x +1) / (x² - x)
2) 1/(x+2) - 2(x-1) = (x-1) - 2(x+2) / ((x+2)(x-1)) = (x-1-2x+2) /(x²-x +2x -2)
= (-x +1) / (x² + x - 2)
3) 1/x +1/(x+1) +2/(x+2) =[ (x+1)(x+2) +x(x+2) +2x(x+1)] / [x(x+1)(x+2)]
= (x²+2x+x+2+x²+2x+2x²+2x) / [x(x²+2x+x+2)]
= (4x²+7x+2) / (x³+3x²+2x)
4) 6x / (2x-1) + (5-4x) / (x+3) = [6x(x+3) +(5-4x)(2x-1)] / [(2x-1)(x+3)]
= (6x²+18x+10x -5 -8x² +4) / (2x²+6x-x-3)
= (-2x²+28x -1) / (2x²+5x-3)
j'espère avoir aidé.
Explications étape par étape
