Răspuns :
a+b=702
a-b=b/4
4a-4b=b
4a-5b=0
a=702-b
4(702-b)-5b=0
2808-4b-5b=0
2808 =9b
b= 312
a=702-312=390
a-b=b/4
4a-4b=b
4a-5b=0
a=702-b
4(702-b)-5b=0
2808-4b-5b=0
2808 =9b
b= 312
a=702-312=390
a+b=702/4 ------------>4a+4b=2808
a-b=b/4
4(a-b)=b
4a=5b ................>5b+4b=2808
9b=2808 b=312