Răspuns:
d=3
Explicație pas cu pas:
a=1/7+1/7:0,5
a=1/7+1/7:5/10
a=1/7+1/7×10/5
a=1/7+10/35
a=15/35
a=3/7
b=(0,75+0,5):6,25
b=1,25:6,25
b=0,2=2/10=1/5
c=1/2:1 1/3+(1/2)^2•1/2
c=1/2:4/3+1/4•1/2
c=1/2×3/4+1/8
c=3/8+1/8=4/8=1/2
d=7a-5b+2c
d=7×3/7-5×1/5+2×1/2
d=3-1+1
d=3