30. 6x - Sy - 30 31. y - -2x + 3 32 y = -3x + 1 - 2 33. Concept Check Consider the patterns formed in the tables for Exercises 23 and 31. Fill in each blank with the appropriate number. () In Exercise 23, for every increase in x by 1 unit, y increases by . unit(s). (b) In Exercise 31, for every increase in x by 1 unit, y decreases by _unit(s). (c) On the basis of your observations in parts (a) and (b), make a conjecture about a similar pattern for y - 2x + 4. Then test your conjecture. 34. Explain why the graph of x + y = k cannot pass through quadrant III if k > 0. 35. A student attempted to graph 4x + Sy - 0 by finding intercepts. First she let x - 0 and found y; then she let y = 0 and found r. In both cases, the resulting point was (0, 0). She knew that she needed at least two points to graph the line, but was unsure what to do next because finding intercepts gave her only one point. Explain to her what to do next 36. Concept Check What is the equation of the x-axis? What is the equation of the y-axis? Find the x- and y-intercepts. Then graph each equation . 37: 2x + 3y = 12 38. 5x + 2y = 10 39. x - 3y - 6 40. x - 2y = -4 41. x - 3y =7 12 1+ 9y- -2 43, y - 5 44. y = -3 45. 1 = 2