You can put this solution on YOUR website! Benilda is one year older than twice her sister's age
Benilda's age will be b and her sister's age will be s.
When we see the word "is", we know to put an equal sign
b=2s+1
The difference of their ages is 18.
b-s=18
We are going to use subsitution because the first equation is already solved for b.
(2s+1)-s=18
combined like terms
s+1=18
subtracted 1 from both sides
s=17
and then we can plug in 17 in for s
b=2*17+1
b=35