Posted by Jaison on Wednesday, October 28, 2009 at 3:47pm.
solve by graphing:
I know that the answer is (-1,2)and i know how to mark the spot but can you explain how to draw the lines because i cant figure out the directions it goes in.
- Math - jim, Wednesday, October 28, 2009 at 4:55pm
To graphing a straight line:
1. Draw your axes.
2. Set x=0 in your equation to get the y-intercept:
x + y = 1
0 + y = 1
y = 1
so we have one point: (0,1)
3. Set y=0 in your equation to get the x-intercept:
x + y = 1
x + 0 = 1
x = 1
so we have a second point: (1.0)
4. Mark the two points on your graph, and use a ruler to draw the straight line that goes through them.
I usually go for the x- and y-intercepts as my points, but any two points will do. Sometimes you can't use two intercepts, as in your second equation:
2x + y = 0
2(0) + y = 0
y = 0
So the origin (0.0) is on this line.
The x- and y-intercepts are the same.
We need another point. No problem; just set x = anything else, for example 3:
2x + y = 0
2*3 + y = 0
y = -6
So we can use the point (3, -6) as our second point. Mark it, and get out the ruler again to draw a straight line through (3, -6) and the origin.
The two lines should meet at the point you expect.
Answer this Question
More Related Questions
- Math - Solve each inequality y+5>7 The arrows are supposed to have lines ...
- Algebra - This will be a multiple post thing so please bear with me. If my ...
- Math - How would I figure this problem out? "To rotate a figure 150 degrees you ...
- graphing - Can someone show me how to solve these inequalties for me? I cannot ...
- algebra - 1)Identify the y-intercept and the axis of symemetry for the graph of ...
- Math - Marks worth is A 1 B 2 C 2 Please explain next to it though how you got ...
- Math - Solve the system by graphing by any method of your choice. 3x-y=1 or y=3x...
- Math Correction - Explain how you can tell(without graphing) that the function ...
- Math - Four classmates are comparing the number of pages that they have read in ...
- 8th grade algebra - We did graphing reflections of images homework from the book...