Answer:
75
Step-by-step explanation:
Scores for his first tests were 65, 67, 69.
Rate of change: +2
y=2x+63; 63 is the 0th test he took, his first test was 65, so 65-2=63. 2x is the rate of change, his tests scores increase by 2 each time.
x=6, 6th test score
y=2(6)+63
y=12+63
y=75
So, on his 6th test he will get a score of 75