Please help me answer this question

Which sum or difference identity would you use to verify that cos (180° - ∅) = -cos ∅? a. sin (α -β) = sin α cos β – cos α sin β b. cos (α -β) = cos α cos β – sin α sin β c. cos (α -β) = cos α cos β + sin α sin β d. sin (α + β) = sin α cos β + cos α sin β

Is the number 128.439 a rational number

Jon’s weight loss for each week of the month is 5 lbs., 2.5 lbs., and 2.5 lbs. he gained 3.5 lbs. the last week. if jon originally weighed 198 lbs., how much does he weigh now?