We know in these kind of triangles that have a 90 degrees angle, we can do:

so the first question:

and then:

so , when you want to rationalize , usually you must multiply the irrational factor as 1:

so , now multiply:

in the next question,we know negative numbers in radical don't have any solution so 2 is correct,
Answer:
Some numbers cannot be written as a ratio of two integers
Step-by-step explanation:
11.25cups. I got that by multiplying 2.5. by 4.5. If she wants to make 4.5 batches and 1 batch uses 2.5 cups, you have to multiply the cups of 1 batch by the number of batches she wants to make.
The answer to your question is 35
Am sorry but it think you have forgotten to write the equation or to add an image