Question

Calculați în două moduri
a)7×(3-9)
b)-4×(-8++12)
c)(-5)×[6-(_2)]
d)(-6)×7+(-6)×9
e)(-5)×(+12)+(-5)×7
f)(-10)×7-(-10)×9​

Answer 1

Răspuns:

a) 7×(3-9)=7×3-7×9=21-63=-42..l

=7×(-6)=-42

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

=-4×4=-16

c) (-5)×(-6-(-2))=(-5)×(-6+2)=30-10=20 l

=(-5)×(-6)-(-5)×(-2)=30-10=20 ll

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

=-6(7+9)=-6×16=-96 ll

e) (-5)×(+12)+(-5)×7=-60+(-35)=-60-35=-95 l

=(-5)(12×7)=(-5)(12+7)=(-5)(19)=-95 ll

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

=(-10)(7-9)=-10×(-2)=20 ll