x=number of corect
y=number of incorrect
5 points for each correct so 5x
-1 point for each incorrect so -y
5x-y=76
solve for x and y
I like putting it into slope intercep tofrm which is y=mx+b
add y to both sides
5x=76+y
subtract 76 from both sides
5x-75=y
y=5x-76
subsitute values for x and get values for y
remember, that julia cannot answer a negative number of incorrect questions so y must be greater than or equal to 0
so solve for minimum
0<5x-76
add 76 to both sides
76<5x
divide by 5
15.2<x
you cannot answer a fraction of a correct quesiton so round up
16 is the minumum number of queswtions correctlyh answered
so
x>16
subsitute 16 for x
y=5(16)-76
y=80-76
y=4
as we subsitute more numbers over 16, we get these points
so (x,y)
(16,4)
(17,9)
(18,14)
(19,19)
(20,24)
(21,29)
(22,34)
(23,39)
x=correct answer
y=wrong answers