Form an equation in x use it to solve for X

4 · 15 = x + 10 + x + 8 + 28
60 = 2x + 46
14 = 2x
x = 7

Sekian,semoga membantu.

(x + 10 + x + 8 + 28) / 4 = 15
2x + 46 = 15 × 4
2x = 60 - 46
x = 14/2
x = 7

Kalau boleh jadikan jawaban terbaik yah.