This method covers problems that only tell you two points on a straight line. Write each point coordinate down in (x,y) form.  Example 2: A straight line passes through points (-1, 2) and (3, -4). Find the y-intercept of this line using the steps below. Slope is a measure of how much vertical distance the line moves for each unit of horizontal distance. You may have heard this described as "rise over run" (riserun{\displaystyle {\frac {rise}{run}}}). Here's how to find these two quantities from two points:  "Rise" is the change in vertical distance, or the difference between the y-values of the two points. "Run" is the change in horizontal distance, or the difference between x-values of the same two points.  Example 2 (cont.): The y-values of the two points are 2 and -4, so the rise is (-4) - (2) = -6.The x-values of the two points (in the same order) are 1 and 3, so the run is 3 - 1 = 2. Now that you know these two values, plug them into "riserun{\displaystyle {\frac {rise}{run}}}" to find the slope of the line.  Example 2 (cont.): slope=riserun=−62={\displaystyle slope={\frac {rise}{run}}={\frac {-6}{2}}=} -3. You can describe a straight line with the formula y = mx + b, where m is the slope and b is the y-intercept. Now that we know the slope m and a point (x,y), we can use this equation to solve for b, the y-intercept. Take the equation in slope-intercept form and replace m with the slope you calculated. Replace the x and y terms with the coordinates of a single point on the line. It doesn't matter which point you use.  Example 2 (cont.): y = mx + bSlope = m = -3, so y = -3x + bThe line includes a point with (x,y) coordinates (1,2), so 2 = -3(1) + b. Now the only variable left in the equation is b, the y-intercept. Rearrange the equation so b is on one side, and you have your answer. Remember, the y-intercept always has an x-coordinate of 0.  Example 2 (cont.): 2 = -3(1) + b2 = -3 + b5 = bThe y-intercept is at (0,5).
اكتب إحداثيات كلا النقطتين. احسب الإزاحة الرأسية والأفقية. اقسم المقابل على المجاور للحصول على الميل. راجع صيغة الميل والتقاطع. عوض بالميل والنقطة فى المعادلة. أوجد قيمة b.