Răspuns :
a+b+c+d=661
b=a+4=>a=b-4
b=c:2=>c=2b
b=d:3=>d=3b
Inlocuim
b-4+b+2b+3b=661
7b=661+4
7b=665
b=665:7=95
a=95-4=91
c=2b=2x95=190
d=3b=3x95=285
91+95+190+285=186+475=661
b=a+4=>a=b-4
b=c:2=>c=2b
b=d:3=>d=3b
Inlocuim
b-4+b+2b+3b=661
7b=661+4
7b=665
b=665:7=95
a=95-4=91
c=2b=2x95=190
d=3b=3x95=285
91+95+190+285=186+475=661
a+b+c+d=661
b=a+4=a=b-4
b=c: 2=c=2b
b=d: 3=d=3b
Înlocuim
b-4+b+2b+3b=661
7b=661+4
7b=665
b=665: 7=95
a=95-4=91
c=2b=2 x 95=190
d=3b=3 x 95=285
b=a+4=a=b-4
b=c: 2=c=2b
b=d: 3=d=3b
Înlocuim
b-4+b+2b+3b=661
7b=661+4
7b=665
b=665: 7=95
a=95-4=91
c=2b=2 x 95=190
d=3b=3 x 95=285