Can you please provide a detailed explanation for 7,8,9

7) Three vectors A , B, and C add together to yield zero: A + B + C =0. The vectors A and C point in opposite directions and their magnitudes are related by the expression A = 2C. Which one of the following conclusions is correct? A) A and B have equal magnitudes and point in opposite directions. B) B and C have equal magnitudes and point in the same direction. C) B and C have equal magnitudes and point in opposite directions. D) A and B point in the same direction, but A has twice the magnitude of B . E) B and C point in the same direction, but C has twice the magnitude of B . 8) The x and y components of a displacement vector are -3.00 m and +4.00 m, respectivel What angle does this vector make with the positive x axis? A) 233 B) 1270 C) -53.0 D) 53.0 E) 37.0 9) The table gives the x and y components of two vectors A and B : Vector x component y component +15 units +10 units B +15 units -10 units Determine the magnitude of the vector sum, A + B. A) 5 units B) 15 units C) 20 units D) 30 units E) 50 units