Let the width of the rectangle be 'w'
According to the question length of the rectangle (l) is three feet more than twice it's width;
l = (2w + 3) ft
Perimeter of rectangle = 78 ft
Formula of perimeter of rectangle = 2(Length + Width)
So,

Width of the rectangle (w) = 12 ft
In order to find the slope of a line, u must use the slope formula. Which is (y2-y1/x2-x1). For example if you had a set of coordinates that are (6,4) and (2,8) you would first sub the 8 from4 which gives you 4. The u do the same with 2 and 6 which gives u 4. After that you divide 4 by 4. and your answer is 1
Answer: this is on the STAR math quiz thing, what did you get, assuming you already do did it.
Step-by-step explanation: