After 9y - 18 = 27 is simplified to 9y = 45, what is the second step to solve for the variable "y"? Is it A. Divide both sides by 45 B. Multiply both sides by 9 C. Multiply both sides by 45 D. Divide both sides by 9 Thank you. I just can't figure these out.

A. find the power of the test, when the null hypothesis assumes a population mean of mu = 450, with a population standard deviation of 156, the sample size is 5 and the true mean is 638.47 with confidence intervals of 95 b. find the power of the test, when the null hypothesis assumes a population mean of mu = 644, with a population standard deviation of 174, the sample size is 3 and the true mean is 744.04 with confidence intervals of 95% c. find the power of the test, when the null hypothesis assumes a population mean of mu = 510, with a population standard deviation of 126, the sample size is 10 and the true mean is 529.44 with confidence intervals of 95