Question

tinh nhanh 

a ) 250+5+5+.............+5 ( có 10 so 5)

b)  11+22+33+44+55

Answer 1

a

= 275 

b 

= 165

đúng k nha 

Answer 2

a,=250+(5*10)

=250+50

=300

b,=(11+22)+(33+44)+55

=33+77+55

=(33+77)+55

=110+55

=165

Answer 3

a) 250 + 5 + 5 +... + 5

= 250 + ( 5*10 )

= 250 + 50 = 300

b) 11 + 22 + 33 + 44 + 55

= ( 11 + 55 ) + ( 22 + 44 ) + 33

= 66 + 66 + 33 = 165