Answer:
A(3) = -6 + (3 - 1) (5)
-6 + (2)(5)
-6 + (10)
4
A(4) = -6 + (4 - 1) (5)
-6 + (3)(5)
-6 + 15
9
A(10) = -6 + (10 - 1) (5)
-6 + (9)(5)
-6 + 45
39
Answer: Should be rational
hope this helps.
The work is incorrect.
(-6) multiplies both terms inside parentheses. For some reason, the student changed the sign of that multiplier for the second term. The second term of the result should have a positive sign, the result of multiplying (-6)(-2/13) = +12/13.