Solve t/he system of linear equations given by x + y = 1 and ax − by = c, where a, b, c are real numbers. Note: The solution in this case will not be numbers but formulas containing a, b, and c. Need help ASAP!!

Without multiplying, tell which product is larger and why. 5 × 1/3 or 5 × 2/3 a)5 × 1/3 because 1/3 is less than 2/3 b) 5 × 1/3 because 1/3 is greater than 2/3 c) 5 × 2/3 because 1/3 is less than 23 d) 5 × 23 because 1/3 is greater than 2/3