Which of the following would best be solved using completing the square

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

Solve by any method (graphing, substitution or linear combination)y = x - 82x + 3y = 1a) (2, -6)b) (5, -3)c) (4, -4)d) (0, -8)i figured it out. the answer is (5, -3)

Solve x+3y=6 and 4x-6y=6 by elimination . show work !