Question

ajutor!!!!!!!!!!!!!!!!!!!!! ex16

Answer 1

a)15(87+13)=15×100=1500
b)2017(2456+2544)=2017×5000=10085000
c)197(489+112-301)=197×300=59100
d)78(13-8+26-1)=78×30=2340

Answer 2

a)   15 × 87 + 15 × 13 = 15 × ( 87 + 13 ) = 15 × 100 = 1 500

b)  2 456 × 2017 + 2017 × 2544 = 2017 × ( 2456 + 2544 ) =

=  2017 × 5000 = 10 085 000

c)   197 × 489 + 197 × 112 - 301 × 197 = 197 × ( 489 + 112 - 301 ) =

= 197 × ( 601 - 301 ) = 197 × 300 = 59 100

d)  78 × 13 - 8 × 78 + 26 × 78 - 78 = 2 340

= 78 × ( 13 - 8 + 26 - 1 ) =

= 78 × ( 5 + 25 ) =

= 78 × 30 =

= 2340