Picture included ^ ( BRAINLIEST)

How do you use the elimination method for this question? explain, because i really want to understand!

Solve the problem. a student earned grades of c, a, b, and a in four different courses. those courses had these corresponding numbers of credit hours: 4, 5, 1, and 5. the grading system assigns quality points to letter grades as follows: a = 4, b = 3, c = 2, d = 1, and f = 0. compute the grade point average (gpa) and round the result to two decimal places. 3.40 3.50 8.75 2.18

In the diagram, gef and hef are congruent. what is the value of x