Answer:
x=18
Step-by-step explanation:
We'll assume that the shorter sides are AB and CD. Then 7x-6=5x+30. You add 6 to both sides. 7x=5x+36. Isolate x. 2x=36. Divide, and x=18.
Is the second one because the books and the costs never will equal.
Answer:

Step-by-step explanation:
Given that,
He makes $10 per hour making sandwiches, and $14 per hour delivering orders.
Let there are s sandwiches and d is delivering orders.
Eric puts half of his total earnings in a savings account for college.
The expression that represents the total amount of money Eric saves for working s hours making sandwiches and d hours delivering orders.

Hence, this is the required solution.