Răspuns :
392-240=152 (suma al treilea +al patrulea)
l---------l al treilea }
l---------l--l+12 al patrulea} 152 suma
1+1=2 segmente egale
152-12=140 (2 segmente egale)
140:2=70 (al treilea)
70+12=82 (al patrulea)
82-4=78 (al doilea)
70+82+78=230 (suma II+III+IV)
392-230=162 (primul)
l---------l al treilea }
l---------l--l+12 al patrulea} 152 suma
1+1=2 segmente egale
152-12=140 (2 segmente egale)
140:2=70 (al treilea)
70+12=82 (al patrulea)
82-4=78 (al doilea)
70+82+78=230 (suma II+III+IV)
392-230=162 (primul)
a+ b+ c+d = 392
a+b= 240
c+12= d
b+ 4 = d
240+c+d= 392
240+d-12+d=392
240+2d-12=392
2d= 392+12-240
2d=404-240
d= 164/2
d= 82
c+12=d
c+12= 82
c= 82-12
c=70
b+4 = d
b= d-4
b= 82-4
b= 78
a+b+c+d= 392
a+ 78+70+82= 392
a+230= 392
a=392-230
a= 162
Verificare
162+78+70+82= 392
a+b= 240
c+12= d
b+ 4 = d
240+c+d= 392
240+d-12+d=392
240+2d-12=392
2d= 392+12-240
2d=404-240
d= 164/2
d= 82
c+12=d
c+12= 82
c= 82-12
c=70
b+4 = d
b= d-4
b= 82-4
b= 78
a+b+c+d= 392
a+ 78+70+82= 392
a+230= 392
a=392-230
a= 162
Verificare
162+78+70+82= 392