nomer 4 dan 5 ya please

4.
laba = pendapatan - biaya
5.000 = 50(1000) - biaya
5.000 = 50.000 - biaya
biaya(TC) = 45.000
TR = P.Q = 50Q
VC = 50% × 50Q
VC = 25Q
TC = FC + VC
45.000 = FC + 25(1000)
45.000 = FC + 25.000
FC = 20.000
TC = 20.000 + 25Q
jadi fungsi
TR = 50Q
VC = 25Q
TC = 20.000 + 25Q

b. titik impas
TR = TC
50Q = 20.000 + 25Q
50Q-25Q = 20.000
25Q = 20.000
Q = 20.000÷25 = 800