Straight line equation easy question

In summary, the conversation discusses how to calculate the slope and find the equation of a straight line. The equation given is -2x+2, and the slope is calculated using the formula y2-y1/x2-x1. The question is then raised about how to find the constant, which is determined to be +2 based on where the line crosses the y-axis. It is clarified that to find a line with a slope of 2, the slope equation y=mx+b should be used.
  • #1
sameh1
9
0
i have an easy question i Know how to calculate the slope but how I can get all the equation I know before that the equation is -2x+2 I know how to calculate the slope it
is y2-y1/x2-x1 but how can I get +2
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  • #2
The constant is the same as the point where the line crosses the y-axis. So in this case you see it crosses at positive 2 so the constant will be +2.
 
  • #3
your question is somewhat confusing...if you are asking how to get a slope = 2, you need a different line. the slope of a straight line is constant. y = -2x +2 is a straight line and you calculated the slope correctly, -2.

To find a line with slope = 2, use slope equation...y=mx+b.
 
  • #4
It's not confusing if you look at the picture
 

1. What is the formula for a straight line equation?

The formula for a straight line equation is y = mx + b, where m is the slope and b is the y-intercept.

2. How do you find the slope of a straight line?

To find the slope of a straight line, you can use the equation m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line. Alternatively, you can use the slope formula, m = rise / run, where rise is the change in y and run is the change in x between two points on the line.

3. What is the meaning of the y-intercept in a straight line equation?

The y-intercept represents the point where the line crosses the y-axis. In other words, it is the value of y when x is equal to 0. It is also known as the initial value or starting point of the line.

4. Can a straight line equation have a negative slope?

Yes, a straight line equation can have a negative slope. This means that the line is decreasing from left to right. The slope represents the rate of change of the line, so a negative slope indicates that the line is decreasing.

5. How do you graph a straight line using its equation?

To graph a straight line using its equation, you can plot the y-intercept first. Then, use the slope to find a second point on the line and plot it. Finally, draw a line through the two points to create the graph of the line.

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