Question

calcule o consciente


A)
$( - 2).( + 3).( + 4)$
B)
$( + 5).( - 1).( + 2)$
C)
$( - 6).( + 5).( - 2)$
D)
$( + 9).( - 2).( - 3)$
​

Answer 1

Olá!

a)

$\left(-2\right)\left(3\right)\left(4\right)\\\\\mathrm{Aplicar\:a\:regra\:}\left(-a\right)\cdot \left(b\right)\:=\:-a\cdot \:b\\\\\left(-2\right)\left(3\right)=-2\cdot \:3=-6\\\\=-6\left(4\right)\\\\=-6\cdot \:4\\\\=-24$

b)

$\left(5\right)\left(-1\right)\left(2\right)\\\\\mathrm{Aplicar\:a\:regra\:}\left(a\right)\cdot \left(-b\right)\:=\:-a\cdot \:b\\\\\left(5\right)\left(-1\right)=-5\cdot \:1=-5\\\\=-5\left(2\right)\\\\=-5\cdot \:2\\\\=-10$

c)

$\left(-6\right)\left(5\right)\left(-2\right)\\\\\mathrm{Aplicar\:a\:regra\:}\left(-a\right)\cdot \left(b\right)\:=\:-a\cdot \:b\\\\\left(-6\right)\left(5\right)=-6\cdot \:5=-30\\\\=-30\left(-2\right)\\\\\mathrm{Aplicar\:a\:regra\:}-a\cdot \left(-b\right)\:=\:a\cdot \:b\\\\\left(-6\right)\left(5\right)=-6\cdot \:5=-30\\\\=-30\left(-2\right)\\\\\mathrm{Aplicar\:a\:regra\:}-a\cdot \left(-b\right)\:=\:a\cdot \:b\\\\-30\left(-2\right)=30\cdot \:2=60\\\\=60$

d)

$\left(9\right)\left(-2\right)\left(-3\right)\\\\\mathrm{Aplicar\:a\:regra\:}\left(a\right)\cdot \left(-b\right)\:=\:-a\cdot \:b\\\\\left(9\right)\left(-2\right)=-9\cdot \:2=-18\\\\=-18\left(-3\right)\\\\\mathrm{Aplicar\:a\:regra\:}-a\cdot \left(-b\right)\:=\:a\cdot \:b\\\\-18\left(-3\right)=18\cdot \:3=54\\\\=54$

Espero ter ajudado, tenha boas aulas!