Question

Помогите
7/9x + 11/12 = 13/18

Answer 1

7/9х + 11/12 = 13/18
28/36х + 33/36 = 26/36
28/36х = 26/36 - 33/36
28/36х = - 7/36
х = - 7/36 : 28/36 = - 7/36 * 36/28
х = - 7/28 = - 1/4
Ответ: х = - 1/4.

Общий знаменатель 36
36 : 9 = 4 - доп.множ. к 7/9 = (7*4)/(9*4) = 28/26
36 : 12 = 3 - доп.множ. к 11/12 = (11*3)/(12*3) = 33/36
36 : 18 = 2 - доп.множ. к 13/18 = (13*2)/(18*2) = 26/36
7/28 = 1/4 - сократили на 7