Question

determine o valor das expressões numéricas.

A) 1-[-2/5-(-1/2+3/4)-0,5]=

B) (-2)-³ - 1/4• [2/3-(-1+1/2)]

Answer 1

1-[-2/5-(-1/2+3/4)-0,5]=
1-[-2/5-(-2/4+3/4)-5/10]=
1-[-2/5-1/4-5/10]=
1-[-8/20-5/20-10/20]=
1-[-23/20]=
1+23/20=
20/20+23/20=
43/20


(-2)^-3-1/4.[2/3-(-1+1/2)]=
(-1/2)^3-1/4.[2/3-(-2/2+1/2)]=
-1/8-1/4[2/3-(-1/2)]=
-1/8-1/4[2/3+1/2]=
-1/8-1/4[4/6+3/6]=
-1/8-1/4.7/6=
-1/8-7/24=
-3/24-7/24=
-10/24=
-5/12