Answer:
Torrance spends 16$ on his brother
Step-by-step explanation:
You have 100$
So, we have
x (brother) + x (sister) + x (mother) = 100
But, since 10$ less will be spent on the sister than the brother, it becomes (x - 10) and twice + 6$ is spent on the mom, it also becomes (2x + 6)
Our equation then becomes
(x - 10) + x + (2x + 6) = 100
X will end up equaling 26. This is how much is spent on the sister.
(x - 10) will be substituted for (26 - 10), which equals 16.
I'm not sure if this is right so you might want to check with somebody (since I may be wrong) I hope this helps you understand how to basically do it though. <3