C. 2+ (-1) = -1 D. 8 + (-9) = -1 17. Which of the following statements is FALSE ? A. (-7) + (-6) = -13 B.(-5) + 1 = 4 18. The sum of two same numberd with unlike signs is always A. Positive B. Negative C. Zero 19. What must be added to 9 if the sum is (-17) ? A. 26 B. -26 C. 12 20. The value of 6-(-3) is A. 3 D. One D.-12 B. -3 C. 9 D. -9 21. Which of the following statements is TRUE? A. 7-4 = 4-7 B, 7-4 > 4-7 C. 7-4 <4-3 D. 7-4 = -3 ic CASE