Tolong dijawab no 1 dan 4 Saja Besok Dikumpulkan Soal kelas 7 Mtk

1.2a+3a = 90
  5a = 90
  a = 18

a+29+5a+15=180-46
6a + 44 = 180-46
6a = 180 - 90
6a = 90
a = 15

2a + 3a = 90
5a = 90
a = 18