Moises is determining the solution to the system of equations that is show below. Equation representing line A: mc018-1.jpg Poin
ts on line B: (3, –12) and (9, –24) Step 1: Determine the slope for B: mc018-2.jpg Step 2: Determine the y-intercept for B: mc018-3.jpg Step 3: Write the equation in slope-intercept form: mc018-4.jpg
Explanation: The general form of the line is: y = mx + c where: m is the slope of the line c is the y-intercept
(a) getting the slope of the line: slope of the line is calculated using the following rule: slope of line (m) = (y2-y1) / (x2-x1) = (-24--12) / (9-3) = -2 The equation now becomes: y = -2x + c
(b) getting the y-intercept: The two given points belong to the line. Therefore, to get the y-intercept, we will use one of the points and substitute in the equation and solve for c. I will use the point (3,-12) y = mx + c -12 = -2(3) + c -12 = -6 + c c = -12 + 6 c = -6
Based on the above, the equation of the line is: y = -2x - 6
