Answer:
1. 
2. 13.5 + 
3. 
6. 
These four options are rational;
Step-by-step explanation:
1.
equals to 10 * 10 = 100 which is rational
2. 13.5 +
equals 13.5 + 9 = 22.5
3.
-- 3+27 = 30
6. 
Option 4 and 5 are irrational because they include
and
which are not a perfect square and their answers will be non recurring and non terminating decimal fraction.
Take another photo I can’t see that clearly
Answer:
Part 1) 
Part 2) 
Step-by-step explanation:
Part 1) Find the value of x
we know that
Triangles CDF and FDE are similar
therefore
The ratio of its corresponding sides is proportional and its corresponding angles are congruent
so


Part 2) Find the length of DE

substitute the value of x

Answer:
x = 1.5
Step-by-step explanation:
First, calculate 6-9, which is -3.
Then we add 9 on both sides so that on the left, we only have 4x, and on the right, we have 6.
Then divide by 4 on both sides to get x = 1.5
7900 79 times 100 ------------