urgent:équations 3ème à résoudre svp: 1) 5(x-1)+2(4x+3)=7x 2) -5(8x+9)=3(7x-3) 3) (2x-7)(5-4x)=9-8xau carré

1/ 5x-5+8x+6=7x
13x+1-7x=0
6x=-1
x=-1/6
S=-1/6
2/ -40x-45=21x-9
-40x-21x=45-9
-61x=36
x=36/-61
S=-36/61
3/(2x-7)(5-4x)=9-8x²
(2x-7)(5-4x)-9+8x²=0
10x-8x²-35+28x-9+8x²=0
38x-44=0
38x=44
x=22/19
S=22/19

5(x -1) +2(4x +3) = 7x
5x -5 +8x +6 = 7x
5x +8x -7x = +5 -6
+6x = -1
x = -1/6

-5(8x +9) = 3(7x -3)
-40x -45 = 21x -9
-40x -21x = +45 -9
-61x = + 36
x = +36/61

(2x-7)(5 -4x) = -9 -8x²
+10x -8x² -35 +28x = -9 -8x²
10x -8x² +28x +8x² = +35 -9
38x = 26
x = 26/38 = 13/19