Tolong bantu jawab soal nomor 1-4 beserta caranya tks

1) 2/8 = 1/4
2) sisa bagian = 1 – (1/5 + 1/4+ 1/3)
                        = 1 – (12/60+15/60+20/60)
                       = 1 – (47/60)
                       = 60/60 – 47/60
                       = 13/60

   sisa tanah = 13/60 x 1200
                    =  13 x 20
                    = 260m²

3) antara 5/6 dan 6/7
    antara 35/42  dan 36/42 = 35,5/42
                                           = 355/420
                                           = 71/84

4) 2a+4b = 2(2/3) + 4(3/4)
               = 4/3 + 3
               = 4/3 + 9/3
               = 13/3
               = 26/6

     5a-2b = 5(2/3) – 2(3/4)
               = 10/3 – 3/2
               = 20/6 – 9/6
               = 11/6
 
   
   2a+4b / 5a-2b = 26/6  /  11/6
                          = 26/11        
  
   

Jwbn nmr 2 adalah b ..