Question

Calcule: a) ( - 7 ) . ( + 3 ) . ( - 2 ) * 1 ponto + 42 - 12 - 42 b) - 4 . ( + 3 - 2 + 5 ) * 1 ponto - 12 - 24 + 24

Answer 1

a) 42

b) -24

Explanation:

Recordar las reglas de los signos:

(-)*(-) = (+)

(+)*(-) = (-)

(-)*(+) = (-)

(+)*(+) = (+)

Tambien la propiedad distributiva:

A*(B + C + D) = A*B + A*C + A*D

Queremos calcular:

a) (-7)*(+3)*(-2)

Los primeros dos terminos dan:

-(7*3)*(-2) = -(21)*(-2) = (-21)*(-2) = +(21*2) = +42

b) -4*( + 3 - 2 + 5)

= (-4)*(3) + (-4)*(-2) + (-4)*(5)

= - 12 + 8 - 20 = 8 - 32 = -24