Question

1 ) Efetue as adições:
a) (-2/5) + 3 =
b) (-1/6) + (+2) =
c) (-5/3) + (+1) =
d) (-4) + (-1/2) =
e) (-0,2) + (-1/5) =
f) (+0,4) + (+3/5) =
g) (-0,5) + (+0,7) =
h) (-02) + (-1/2) =​

Answer 1

Resposta:

1)

a) 1/5

b) 11/6

c) -2/3

d) -7/2

e) -2/5

f) 1

g) 0,2

h) -5/2

Explicação:

1)

a) (-2/5)+3 =

-2/5+3/1 =

[(5÷5×(-2)]+[5÷5×3]/5 =

[1×(-2)]+[1×3]/5 =

-2+3/5 =

1/5

b) (-1/6)+(+2) =

-1/6+2 =

-1/6+2/1 =

[6÷6×(-1)]+[6÷1×2]/6 =

[1×(-1)]+[6×2]/6 =

-1+12/6 =

11/6

c) (-5/3)+(+1) =

-5/3+1 =

-5/3+1/1 =

[3÷3×(-5)]+[3÷1×1]/3 =

[1×(-5)]+[3×1]/3 =

-5+3/3 =

-2/3

d) (-4)+(-1/2) =

-4-1/2 =

-4/1-1/2 =

[2÷1×(-4)]+[-2÷2×(-1)]/2 =

[2×(-4)]+[-1×(-1)]/2 =

-8+1/2 =

-7/2

e) (-0,2)+(-1/5) =

-0,2-1/5 =

-0,2/1-1/5 =

[5÷1×(-0,2)]+[5÷5×(-1)]/5 =

[5×(-0,2)]+[1×(-1)]/5 =

-1+[-1]/5 =

-1-1/5 =

-2/5

f) (+0,4)+(+3/5) =

0,4+3/5 =

0,4/1+3/5 =

[5÷1×0,4]+[5÷5×3]/5 =

[5×0,4]+[1×3]/5 =

2+3/5 =

5/5 = 1

g) (-0,5)+(+0,7) =

-0,5+0,7 =

0,2

h) (-02)+(-1/2) =

-2-1/2 =

-2/1-1/2 =

[2÷1×(-2)]+[2÷2×(-1)]/2 =

[2×(-2)]+[1×(-1)]/2 =

-4+[-1]/2 =

-4-1/2 =

-5/2