The answer to this is f(x) = (3/2)x - 2.
Wish I can help , but you didn’t show any fractions nor anything I can use to answer your question . Can you mark me brainliest for effort !?
So average is of the first 6 tests is 82 well that means
(test1 + test2+ test3+ test4 + test5+test6)/6 = 82
so now let do some cross multiplliying
test1 + test2 + test3 + test 4 + test5 +test6 = 82*6
test1 + test2 + test3 + test 4 + test5 +test6 = 492
now lets see if we can find that 7th test score
(test1 + test2 + test3 + test4 + test5 +test6 + test7)/7 = 80.5
So look we found test1 + test2 + test3 + test4 + test5 +test6 to be 492 so lets substitute.
(492 + test7 )/7 = 80.5
test7 = (80.5*7)-492 = 71.5
C is the answer hope that helps have a good day
long way
12 x 11 x 10 x 9 x 8 x 7 x6 x5 x4 x3x2/ 10x9x8x7x6x5x4x3x2x
but you can shorten that by crossing out identical numbers so you get 12 x 11
12 x 11 = 132 combinations