What is the slope of y=-x perpendicular to the equation

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table

Sandy is upgrading her internet service. fast internet charges $20 for installation and $52.45 per month. quick internet has free installation but charges $57.45 per month. part 1 out of 2 complete the equation that can be used to find the number of months after which the internet service would cost the same. use the variable x to represent the number of months of internet service purchased.

Below are statements that can be used to prove that the triangles are similar