Answer and Step-by-step explanation:
Let's try to add these two mixed numbers together. We have
and
.
First, add the nonfractional parts together:
1 + 2 = 3
Now add the fractional parts. Because 3/10 and 5/10 already have a common denominator (10), we can simply add the numerators together:

Add 8/10 to our whole number 3:
3 + 8/10 = 
Clearly,
≠ 5, which is why 1 3/10 + 2 5/10 ≠ 5.
Hope this helps!
Answer:
Did you mean 3.50x? If so, It would be (1.2, 2.2). If you meant just 3.50, it would be (1.56, 1.5)
Hope this helps!
All of them are equivalent expressions, except for the fourth one
Answer:
It's C
Step-by-step explanation: