Răspuns :
a+b=431 =>a=431-b
2a+5b=1696
2(431-b)+5b=1696
862-2b+5b=1696
3b=1696-862
3b=834 =>b=278
a+278=431 =>a=153
2a+5b=1696
2(431-b)+5b=1696
862-2b+5b=1696
3b=1696-862
3b=834 =>b=278
a+278=431 =>a=153