B=12+2x6+2÷(9-7)
=12+12+2/2
=24+1
=25
C=9+9-2÷2+3x9
=18-1+27
=17+27
=44
D=5,2x(6,3+4,4)-(3,8+5,2)
=5.2*10.7-9
=55.64-9
=46.64
E=6,9+3,6x8,9+7,3+5,9
=6.9+32.04+7.3+5.9
=52.14
Exercice2
a)x/2=48/12
x=48/12*2
x=96/12
x=8
b)8/5=64/x
8/5*1/64=1/x
1/40=1/x
x=40
c)x/16=9/4
x=9/4*16
x=36
d) 4/8=x/16
4/8*16=x
x=8
e)1/6=x/24
1/6*24=x
x=4
f) x/9=7/3
x=7/3*9
x=21