Concept:Parallel lines have equal slopes. Use the slope from the given two points, then form the equation through (6,−13).Explanation:Slope of the line through (7,4) and (−3,9) is:m=x2−x1y2−y1=−3−79−4=−105=−21Since line L is parallel to this line, its slope is also m=−21.The equation of a line with slope m passing through (x1,y1)=(6,−13) is:y−y1=m(x−x1)y−(−13)=−21(x−6)y+13=−21x+3y=−21x+3−13y=−21x−10Answer:y=−21x−10 (Option C)