Bonjour,
Ex 8:
a. 1/2= 1/3+x
x= 1/2-1/3
x= (1*3-1*2)/6
x= 1/6 S= 1/6}
b. (x/5)+1-(3/10)= 0
x/5= -1+3/10
x/5= (-1*10+3)/10
10x= 5(-7)
x= -35/10 on simplifie par 5
x= -7/2 S= { -7/2}
c. 7/3-x/9= 2
-x/9= 2- 7/3
-x/9= (2*3 -7)/3
-3x= 9(-1)
x= -9/-3
x= 3 S= { 3 }
Ex 9:
a. x-2/3= 11 * 2/3
x= 22/3+2/3
x= 24/3
x= 8 S= {8}
b. ax= 2a
x= 2a/a
x= 2 S= {2}
c. x+a= a
x= a-a
x= 0 S= { 0 }
d. x/7-7= 0
x/7= 7
x= 7*7
x= 49 S= {49}
