Q. A line that includes the points (9,−10) and (7,j) has a slope of −9. What is the value of j?j=___
Understand the slope formula: Understand the formula for the slope of a line. The slope m of a line passing through two points (x1,y1) and (x2,y2) is given by the formula m=x2−x1y2−y1.
Apply formula to given points: Apply the slope formula to the given points and slope.We know the slope m=−9, and we have the points (9,−10) and (7,j). Let's plug these into the slope formula:−9=7−9j−(−10)
Simplify the equation: Simplify the equation.−9=(7−9)(j+10)−9=(−2)(j+10)
Solve for j: Solve for j.To find j, we need to multiply both sides of the equation by −2:−9×−2=(j+10)18=j+10
Subtract 10 to isolate j: Subtract 10 from both sides to isolate j.18−10=j8=j
More problems from Find a missing coordinate using slope