Răspuns :
a+b=90
a:b=2 rest 15
a/--/
b/--/--/+15 }90
90-15=75
75:3=25(a)
25×2+15=65(b)
a+b=90
a:b=2 rest 15
a=2×b+15
2b+15+b=90
3b=90-15
3b=75
b=75:3
b=25
a=90-25
a=65
Verific:65:25=2 rest 15 => (corect)
a+b=90
a:b=2 rest 15
a/--/
b/--/--/+15 }90
90-15=75
75:3=25(a)
25×2+15=65(b)
a+b=90
a:b=2 rest 15
a=2×b+15
2b+15+b=90
3b=90-15
3b=75
b=75:3
b=25
a=90-25
a=65
Verific:65:25=2 rest 15 => (corect)