Using Rstudio, conduct a statistical analysis:

A two-arm randomized controlled trial is being planned with participants in the Framingham Health Study. The study will randomly assign pre-hypertensive participants to receive either a 'new drug' or 'placebo' in order to measure their change in systolic blood pressure after 2 months. The investigators have specified the variance of differences (before minus after) in SBP to be 20 units (20 mmHg2 ) for both groups. What sample size is needed per group to detect a difference in mean changes of at least 3 units (3 mm Hg) with a 95% confidence level ( = 0.05) and 80% power.

I also want to understand if this is a two-sample equation or a one-sample equation? It seems to be a two-sample equation.