Question

Calculați în două moduri :

a) 3 supra 5 ori( 1 supra 9 +4 supra 9)
b)1 supra 7 ori(7 supra 15-3 supra 10)
repede va rog ca dau coroana​

Answer 1

Răspuns:

a) 3/5 × (1/9+4/9)=

=3/5×5/9=

=3/9×5/5=1/3×1=1/3

3/5 × (1/9+4/9)=

=3/5×1/9 + 3/5×4/9=

= 3/45 + 12/45=

=15/45=

simplificăm prinv5

=3/9=

simplificm prin 3

=1/3

b) 1/7× (7/15-3/10)=

=1/7 × (7×2/15×2 - 3×3/10×3)=

=1/7 × (14/30-9/30)=

=1/7 × 5/30=

=5/210=

=1/42

1/7× (7/15-3/10)=

=1/7×7/15-1/7×3/10=

=1/15×7/7-1/7×3/10=

=1/15×1-3/70=

=1/15-3/70=

=14/15×14-3×3/70×3=

=14/210‐9/210=

=5/210=

=1/42