Question 897391
a+b=140,
5.5*a+3.5*b=4.5*140
a=140-b
5.5*(140-b)+3.5*b=630
770-5.5b+3.5*b=630
-2*b=-140
b=70
a=140-b
a=70 b=70
check
5.5*70+3.5*70=4.5*140
385+245=630
630=630
ok