Question

conta correta .............

Answer 1

2 -  y + 5     =  y + 1
      ---------     ---------
          9             12

36.2 - 4.(y + 5)        3.(y + 1)
--------------------  = ---------------
      36                           36

72 - 4y - 20 = 3y + 3
72 - 20 - 4y = 3y + 3
52 - 4y = 3y + 3
52 - 3 = 3y + 4y
49 = 7y
7y = 49
y = 49/7
y = 7

R.: y = 7
*****************************
Obs.: mmc (9,12) = 36

9,12: 2
9,6: 2
9,3: 3
3,1: 3
--------------
1,1   = 2.2.3.3 = 4.9 = 36