Please help me with solving only question (a)

Make sure to answer both the questions. Thanks a lot!

A large university keeps track of its students when they enter the labor market after leaving school. Specically, they collect data on their students' starting salaries (in thousands of U.S. dollars), gender, and whether the student graduated from a STEM (science, technology, engineering, maths) eld. These variables are denoted inc, male, and stem, respectively. The following model is then estimated using 0L3 me:- = (3-9 + lmaiez- + ug- (1) (a) Take the expectation of equation [1) conditional on male = 1 and male = I] [one at a time). What is ,31 equal to? How do you interpret .31