Why is 1 not prime??explain why

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?

What is the value for this expression? 2e-5

Will mark brainliest for correct answer! i have been on this problem for an hour and can't find the answer. i'm begging here! incase you cant read the instructions in the picture because of too much or too little lighting: note: enter your answer and show all the steps that you use to solve this problem in the space provided.write a list of steps that are needed to find the measure of b. provide all steps as clear as possible, !