Resposta:
Explicação passo a passo:
a) -8+10=2
b)-70+40=-30
c)+20-500=-480
d)-1+100=99
2)
[tex]\left(2\right)+\left(-8\right)+\left(7\right)-9+40\\\left(2\right)-8+\left(7\right)-9+40\\-6+\left(7\right)-9+40\1-9+40\\-8+40\32[/tex]
3)
a
[tex]\left(-8\right)-\left(-2\right)\\-8+2\\-6[/tex]
b
[tex]\left(-10\right)-\left(-2\right)-\left(-3\right)+\left(1\right)\\\left(-10\right)+2-\left(-3\right)+\left(1\right)\\-8-\left(-3\right)+\left(1\right)\\-8+3+\left(1\right)\\5+\left(1\right)\\-4[/tex]
c
[tex]\frac{100}{-4}=-25[/tex]
d
[tex]\frac{-80}{-5}=\frac{80}{5}=16[/tex]
4)
1\2 equivale a 0,5 entao 0,5+0,5= 1
b
[tex]3\div \frac{1}{5}=\frac{3}{1}\div \frac{1}{5}=\frac{3}{1}\times \frac{5}{1}=3\times \:5=15[/tex]
