... 10. e) 15.5. 16. If -3x+4y=28 and 3x-2y=8, what is the product of x and y? a) 428. b) 62 2. c) 464 . d) 264 . e) 64 2. 17. If X+Y = 2X-2Z, X-2Y = 4Z and X+Y+Z = 21, what ... 18. If X/Y = 3X and Y = 4-X, what can be the value of 2X? a) Seven and two thirds. b) Three and one third. c) Seven and one third. d) Two and one third. e) Three and two thirds. ... 16. b) 64 . c) 8. d) 4. e) 12. 6. If (A+B) = 4, (B+C) = 9 and (C+D) = 3, what is the value of (A+D)? a) -2. b) 2. c) 7. d) 8. e) 16. 7. If X2 + Y2 = A +3, XY = 7 and...