Question

Calculați aducând la același numitor a) 1/15+2/3; b)3/7+9/14; c) 2/3+1/6; d) 8/9+5/18. Va rog dau coroană!

Answer 1

Răspuns

Explicație pas cu pas:

a)   1 / 15 + 2 / 3 = 11 / 15

        =>  amplific fractia 2 / 3  cu 5    

= 1 / 15 + ( 2 × 5 ) / ( 3 × 5 ) =

= 1 / 15 + 10 / 15 =

= 11 / 15

_______________________

b)   3 / 7 + 9 / 14 =

  =>  amplific fractia 3 / 7 cu 2

= ( 3 × 2 ) / ( 7 × 2 ) + 9 / 14 =

= 6 / 14 + 9 / 14 =

= ( 6 + 9 ) / 14 =

= 15 / 14  =

= 1 intreg si 1 / 14

________________

c)   2 / 3 + 1 / 6 = 5 / 6

=>  amplific fractia 2 / 3 cu 2

= ( 2 × 2 ) / ( 3 × 2 ) + 1 / 6 =

= 4 / 6 + 1 / 6 =

= 5 / 6

__________________

d)    8 / 9 + 5 / 18 = 21 / 18

   =>  amplific fractia 8 / 9 cu 2

= ( 8 × 2 ) / ( 9 × 2 ) + 5 / 18 =

= 16 / 18 + 5 / 18 =

= ( 16 + 5 ) / 18 =

= 21 / 18 =

= ( 21 : 3 ) / ( 18 : 3 ) = =>  simplific fractia cu 3

= 7 / 6 =

= 1 intreg si 1 / 6