Hello Kiddo.
This question is a bit confusing to me, but I think I grasped the concept.
1. x best represents Sarah's mom's age.
2. x - 24 best represents Sarah's mom's age minus how much younger Sarah is than her mom.
3. The expression would look a little like this:
2x-24 = 68
+ 24 +24
2x = 92
/2 /2
x = 46.
Which means, Sarah is 22 and her mom is 46 years of age.
If you need more clarification, I'd be more than happy to elaborate further.
