Drawing Exercises

I really don't understand these questions so please help me.?

In Exercises 45,47,49,and 51, find the general form of the equation of the line that passes through the points. Use a graphing utility to sketch the line. 45. (-8,1), (-8,7) 47. (2, 1/2), (1/2, 5/4) 49. (-1/10, -3/5), (9/10, -9/5) 51. (1, 0.6), (-2, -0.6) In Exercises 55 and 57, write an equation of the line that passes through the points. 55. x-intercept: (2,0) y-intercept: (0,3) 57. x-intercept: (-1/6,0) y-intercept: (0,-2/3)

Public Comments

1. for 45. go to the left 8 spaces and up one space and the to the left 8spaces and up 7 spaces when it's negative go to the left on the graph if it's the first number and down on the graph when it's the second number when it's positive go to the right on the graph if it's the first number and up on the graph when it's the second number for 55. your x axis is the line that goes horizontally so your x intercept would be over to the right 2 spaces and your y axis is the line that goes vertically so your y intercept would be up 3 spaces. it's the same concept as your questions before except this time your looking for where the line crosses on the x and y axis'
2. Here is how you can always find the equation of a straight line that passes through two points you are given: If the two points you are given are (x1, y1) and (x2, y2), using the numbers like subscripts, then the line is y - y1 = [(y2 - y1) / (x2 - x1)] (x - x1). Example: The equation of the line that passes through (0.5, 3) and (1, -2.5) is: y - 3 = [(-2.5 - 3) / (1 - 0.5)] (x - 0.5) = [(-5.5)/(0.5)] (x - 0.5) = (-11)(x - 0.5) or y = -11(x - 0.5) +3 or y = -11x + 8.5 check by replacing (x,y) with the two points given: 3 = -11(0.5) +8.5 = - 5.5 + 8.5 = 3 okay - 2.5 = -11(1) + 8.5 = -11 + 8.5 = - 2.5 okay
3. Advice: Do yourself your homework or you will not know anything. Hint: 45) -8y and the line is parallel to Oy, intersecting Ox in (-8).