Which linear expression would you add to -8b+5 to have a sum of -b?

The perimeter of a square is80-64y units. which expression can be used to show the side length of one side of the square?

Talia took the bus from her home to the bank and then walked back to her home along the same route. the bus traveled at an average speed of 40 km/h and she walked at an average speed of 5 km/h. to determine the time, x, that it took talia to walk home, she used the equation 40(0.9 – x) = 5x. the time of trip 2 is hours. the distance of trip 1 is km.

Using the rise/run counting method, the slope of the line is