Can somebody help me with this :) ??

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?

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