Maria = x
Tom = y
Use substitution
x+y=30
2y=x
2y+y=30
3y=30
y=10
Tom is 10 years old.
x+y=30
x+10=30
x=20
Maria is 20 years old.
(x/5)-6=2
It depends by difference of. Difference between is more specific.
Answer: I am really good at math so if you need help just say so
Add the similar variables (think apple+apple), in this case, we would add 2q+4q.
Well, what is 4 apples plus 2 apples? 6 apples, simply, 6q
Since 3 is without a variable, we will leave it as is
Therefore, 2q+4q+3= 6q+3
Hope this helped :)