Question

Calcule o valor das expressões numéricas:

a. 15 + (–8) . (+3) =

b. (–30) ÷ (–5) – (–4) =

c. 21 – (–14) ÷ (+2) =

d. (–4) . (–6) – (–6) =

e. 3 .(–8) –4 . (–5) =

f. (–5) .(+4) + (–15) ÷ (–5)

g. (–6) . (+3) + (–5) . (–4) =

h. (–20) ÷ (–5) – (–2) . (–8) =

i. (–9 – 3) ÷ (–2 + 6) =

j. (–5 + 3) . (–2 + 7) =

Answer 1

Boa noite. 

a. 15 + (–8) . (+3) =
15+(-24) = 
15-24 = -9

b. (–30) ÷ (–5) – (–4) =
6+4 = 10

c. 21 – (–14) ÷ (+2) =
21-(7) = 
21-7 = 14

d. (–4) . (–6) – (–6) =
24+6 = 30

3. (–8) –4 . (–5) =
(-8)+20 =  
-8+20 = 12

f. (–5) .(+4) + (–15) ÷ (–5) = 
-20+3 = -17

g. (–6) . (+3) + (–5) . (–4) =
-18+20 = 2

h. (–20) ÷ (–5) – (–2) . (–8) =
4-(16) = 
4-16 = -12

i. (–9 – 3) ÷ (–2 + 6) =
(-12):(4) = -3

j. (–5 + 3) . (–2 + 7) =
(-2).(5) = -10

Regras dos sinais:

+ com + = +
- com - = +
- com + = -
+ com - = -

Bons estudos! :-)