1. solve the system by substitution.
[-2.5x+y=13.5
12.25x - y=-12.25
(-5.1)
(-1,5)
(1.-5)
(5.-1)

Is a currency whose value is tied to another currency, meaning that the exchange is fixed

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.