What is the x value for the solution to the system of equations? Can someone help plz I can’t seem to figure it out!

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Arectangular exercise mat has a perimeter of 36 feet the length of the mat is twich the width writeand solve an equation to determine the length in feet. of the mat then find the area in square feet of the mart

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?