Question

Calculati in doua moduri:
a) 7 x (3-9);
b) -4 x ( -8 + 12);
c) (-5 x [6-(-2)]
d) ( -6)x 7 + (-6) x 9;
e) (-5) x (+12) = (-5) x 7;
f) ( -10) x 7 - (-10) x 9.

Answer 1

a) 7 x (3-9) =7×(-6)= -42
7×3-7×9=21-63= -42

b) -4 x ( -8 + 12)=-4×4= -16
-4×(-8)+(-4)×12=32-48= -16

c) (-5 x [6-(-2)]=-5×8= -40
-5×6-(-5)×(-2)=-30-10 = -40

d) ( -6)x 7 + (-6) x 9=-42-54= -96
(-6)×(7+9) =-6×16= -96

f) ( -10) x 7 - (-10) x 9=-70+90= 20
(-10)×(7-9)= -10×(-2) = 20