Răspuns:
Explicație pas cu pas:
363+a+242=726
a+605=726
a=726-605
a=121
(21+51):9*(153-b)=96
72:9*(153-b)=96
8*(153-b)=96
153-b=96:8
153-b=12
b=153-12
b=141
(c:4+78):10+65=75
(c:4+78):10=75-65
(c:4+78):10=10
c:4+78=10*10
c:4+78=100
c:4=100-78
c:4=22
c=22*4
c=88
Sp=P/2=(141+121+88)/2=(262+88)/2=350/2=175
