tolong dijawab pake cara ya. terimakasih

sr/sr+4= 6/9
sr = 2/3 x sr+4
sr = 2sr +8/3
sr-2sr/3 =8/3
3sr -2sr/3=8/3
sr/3=8/3(kali silang)
24=3sr
sr =24/3 =8
#pr = ps +sr
= 4+8 =12