a l aide pour les aquation ex 39

a) 2 ( x - 5 ) = 3 ( -x + 5 ) 
2x - 10 = - 3x + 15
2x + 3x = 15 + 10
5x = 25
x = 25 / 5
x = 5 

b) - ( - a + 3 ) = 5 ( 3 - a ) + 2 
a - 3 = 15 - 5a + 2
a + 5a = 15 + 2 + 3 
6a = 20
a = 20 / 6
a = 10/3

c) m - ( 5 - 2m ) = 3m + 4 
m - 5 + 2m = 3m + 4 
3m - 5 = 3m + 4
3m - 3m = 4 - 5 
0m = - 1 
Impossible ... 

a)
2(x-5)=3(-x+5)
2x-10=-3x+15
2x+3x=15+10
5x=25
x=25/5=5

b) -(-a+3)=5(3-a)+2
a-3=15-5a+2
a+5a=15+3+2
6a=20
a=20/6=10/3

c) m-(5-2m)=3m+4
m-5+2m=3m+4
m+2m-3m=5+4=9