Answer:
80
Step-by-step explanation:
first, put in (5x-4) for the x in g(x).
g(f(x))=(5x-4)^2 -1
now, FOIL and simplify.
25x^2-40x+16-1
25x^2-40x+15
now, plug in -1 for x.
25(-1)^2-40(-1)+15
25+40+15
80
6 inches because area= length times width and 6 times 8= 48 inches
The perimeter of each is the sum of the lengths of its sides.
Triangle Perimeter = 16 + 4x-3 +3x = 7x+13
Square Perimeter = 2x +2x +2x +2x = 8x
If these are equal, you have

The length of a side of the square is 26 units.
If you mean parallel to another line, you have to find the the equation of that line. Lets just say it was y= 7x-2. To find the slope of a line parallel to that, then you look at the slope of that line, which in this case would be 7. The slope of a line parallel would have to be the same. So, I can't give you a direct answer because I can't see the graph but that is how you get the answer.