saya minta bantuannya jawab 2 soal mtk ini pake cara biar saya lebih mengerti

30x + 15y ≤ 15×30 [÷15]
2x + y ≤ 30 [×2] = 4x + 2y ≤ 60
24x + 30y ≤ 24×30 [÷6]
4x + 5y ≤ 120 eliminasi
4x + 2y ≤ 60
------------------ _
3y = 60
y = 20
2x + 20 = 30
2x = 10
x = 5

titik (0,24)
f(0,24) = 5(0) + 3(24) = 72
f(15,0) = 5(15) + 3(0) = 75
f((5,20) = 5(5)) + 3(20) = 25 + 60 = 85
nilai maks 85