PLEASE HELP! I HAVE BEEN STUCK FOR HOURS! A student's grade in a course is the average of 4 test grades and a final exam that is worth four times as much as each test. Suppose a student has test grades of 90, 89, 80, and 93. Write an equation to model this situation where xis the student's grade on the final exam and y is the student's average for the course.

Step-by-step explanation:

Since the final exam worth 4 times as much as each test,

Each test= 1 unit of total score

Final exam= 4 units of total score

Total= 4(1)+4 = 8 units

Total score

=1/8(90)+1/8(89)+1/8(80)+1/8(93)+4/8x

= 44 +4/8x

Average= Total score/ number of tests

Y= (44+1/2x )÷5

Y= 44/5 +1/10x

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk