1. a+b+c=201
a:b=1 r23 adica a=b+23
b:c=3 r12 adica b=3c+12
acum inlocuim in suma
b+23+b+c=201
3c+12+23+3c+12+c=201
7c+47=201 , 7c=201-47 , 7c=154 , c=154:7 , c=22
si acum b=3x22+12 , b=78
a= 78+23 , a=101
2. a=4b
3a+2b=28 aici inlocuim
3x4b+2b=28 , 14b=28 ,b=28:14 , b=2
a=4x2 , a=8
3. a+b=25 , c=16
axc+bxc= ax16+b+16=16(a+b)= 16x25=400
