We have to add 8/15 to 2/5.
To add two fractions we have to make them have the same denominator, so we have to convert 2/5 to have a denominator of 15. To do this, we have to multiply 2/5 by 3 and then we can add the fractions:

Answer: 14/15
Answer:
The second choice 
Step-by-step explanation:
The missing image is attached
We use the section formula:

We substitute
and m=5, n=9

We simplify to get:

This simplifies to:

In decimals we get:

Answer:
RS=13
Step-by-step explanation:
RS+ST=RT
2w+1+w-1=18
3w=18
w=6
RS= 2w+1= 2(6)+1= 12+1= 13
The student had a 40% error estimate