Answer:
<h2><u><em>
x = 5</em></u></h2>
Step-by-step explanation:
What is the X
3x +15 and 2x + 20
assuming that the question is an equation
3x + 15 = 2x + 20
3x - 2x = 20 - 15
x = 5
-----------------
check
3 * 5 + 15 = 2 * 5 + 20
30 = 30
the answer is good
Solution:

Answer:

<em>Hope this was helpful.</em>
Answer:
Let's suppose that one cubic foot of marble is x.
20x = 3400
But because the weight has a range of +-100, then 20x is between 3300 and 3500. Write it like this:
3300<20x<3500
Divide by 20:
165<x<175
The meaning of this is that one cubic foot of marble weight between 165 and 175 pounds
I believe for the first part x would equal -2 and y would equal -1
hope this helps!