Question

Escreva, no caderno, o resultado das operações na forma decimal
A) -3,1+ ( 2,4-3,8)-(1,6-2)
B) -9/2+[-1-(-5/8+1/4)]
C) 7/3-[2-(1/3-1)]
D) 1/8+(-1/4)

Answer 1

$A) \\ -3,1+ ( 2,4-3,8)-(1,6-2)\\ -3,1+ ( -1,4)-(-0,4)\\ -3,1-1,4+0,4=-4,1\\ \\ B) \\ -\frac{9}{2}+[-1-(-\frac{5}{8}+\frac{1}{4})]=\\ -\frac{9}{2}+[-1-(-\frac{3}{8})]=\\ -\frac{9}{2}+[-\frac{5}{8}]=\\ -\frac{9}{2}-\frac{5}{8}=-\frac{41}{8}\\ \\ C)\\ \frac{7}{3}-[2-(\frac{1}{3}-1)]\\ \frac{7}{3}-[2-(-\frac{2}{3})]\\ \frac{7}{3}-[2+\frac{2}{3}]\\ \frac{7}{3}-[\frac{8}{3}]=-\frac{1}{3}\\ \\ \\ D)\\ \frac{1}{8}+(-\frac{1}{4})=\\ \frac{1}{8}-\frac{1}{4}=-\frac{1}{8}$

Answer 2

Basta segui as normas da expressão numérica.

A)

-3,1 + ( 2,4-3,8)-(1,6-2)=

-3,1 + (-1,4)-(-0,4)=

-3,1 - 1,4 + 0,4=

-4,5 + 0,4 =

-4,1 → Resposta:)

B)

-9/2+[-1-(-5/8+1/4)]=

-9/2+[-1-(-20+8/32)]=

-9/2+[-1-(-12/32)]=

-9/2+[-1+12/32]=

-9/2+[-32/32+12/32]=

-9/2+[(-32+12)/32]=

-9/2+[-20/32]=

-9/2 - 20/32=

(-288-40)/64=

-328/64=

-41/8 → Resposta:)

C)

7/3-[2-(1/3-1)]=

7/3-[2-(1/3-3/3)]=

7/3-[2-(-3+1/3)]=

7/3-[2-(-2/3)]=

7/3-[2+2/3]=

7/3-[6/3+2/3]=

7/3-[6+2/3]=

7/3-[8/3]=

7/3-8/3=

(7-8)/3=

-1/3 → Resposta:)

D)

1/8 + (-1/4)=

1/8 - 1/4 =

(4-8)/32=

-4/32=

-1/8 → Resposta:)