9. Answer: x=4 Slope formula is y2-y1/ x2-x1. The slope will become undefined if the denominator, which is x, has a value of zero. That means the graph function would look like x=.... If the line passes point (4,3) equation of the line would be x=4
10. Answer: y=5 Slope formula is y2-y1/ x2-x1. The slope will become zero if the numerator, which is y, has a value of zero. The function would look like y=..... The equation of the line that pass point (2,5) would be y=5
11. Answer: y=6 A line that parallel with x-axis would be a line with zero slopes and the function would be y=.... If the line passed through (1,6) the equation of the line would be y=6
12. Answer: x=-2 A line that parallel with y-axis would be a line with undefined slopes and the function would be x=.... If the line passed through (-2,4) the equation of the line would be x=-2
13. Answer: y=40 If y varies directly as x, the ratio of x:y would be kept same. It means, the ratio of y1/x1 will be equal to y2/x2. The coordinate is : x1,y1= (5,10) x2,y2= (20, ?) The y when x=20 would be: y1/x1=y2/x2 10/5= y2/20 y2= 2*20= 40
14. Answer: y=24 Same as above, if y varies directly as x, the ratio of x:y would be kept same. It means, the ratio of y1/x1 will be equal to y2/x2. The coordinate is : x1,y1= (10,8) x2,y2= (30, ?) The y when x=30 would be: y1/x1=y2/x2 8/10= y2/30 y2= 0.8*30= 24
15. Answer: x=60 If y varies directly as x, the ratio of x:y would be kept same. It means, the ratio of y1/x1 will be equal to y2/x2. Be careful because this problem is asking for x, not the y variable. The coordinate is : x1,y1= (20,5) x2,y2= (x2, 15) The x2 when y=15 would be: y1/x1=y2/x2 5/20= 15/x2 x2= 15 /0.25 = 60
