Kak nomor 16 dibantu y sekalian pake cara maaf kalo ngerepotin​

4a = 130
a = 32,5

3b-9=81
b = 30

180-81= 2c+11
88 = 2c
c= 44

5x+4=49
x = 9

180-49=8y-5
8y = 136
y = 17

xxxunknownxxx