Bonsoir,

8*x +1= 40 -5*x

x= 1

8*x +1=8+1= 9

40 -5*x= = 40- 5 = 35

35 ≠9

faux!

x= 2

8*x +1=  8*2 +1 = 16 +1 = 17

40 -5*x = 40 - 5*2 = 40 -10 = 30

17≠30

faux

x=3

8*x +1=  8* 3+ 1 = 24+1 =25

40 -5*x =40 -5*3=  40 - 15 =25

25=25

Vrai