A) A perpendicular line to one side of a triangle.
Explanation:
The converse of the triangle proportionality theorem states "<span>If a line divides two sides of a triangle proportionally, then that line is parallel to the third side."
The AA similarity theorem is part of this, as we are looking at the ratios of the sides. Proportionality of the sides is part of this, as it is stated in the converse. A parallel line to one side of a triangle is part of this, again as it is stated in the converse.</span>
Step-by-step explanation: first you collect like terms 8x-7x=1-5 then we do 8x-7x which would equal 1x or just x next we do 1-5 which equals 4 so the solution to this equation is x=-4