5x⁴ - 3x³ + 6x) - (3x³ + 11x² - 8x)<span>
</span>Expand the second bracket by multiplying throughout by -1
5x⁴ - 3x³ + 6x - <span>3x³ - 11x² + 8x
</span>
Group like terms and simplify
5x⁴ - 3x³ - 3x³ - 11x² + 6x <span>+ 8x
</span>5x⁴ - 6x³ - <span>11x² + 14x</span>
Eight units I'm pretty sure
Width = 4ft
Length = 6ft
<u>Explanation:
</u>
Let length = l ,
So, width = 2l-8
Perimeter of rectangle = 2x(length + width)
According to the question,

Hence,
Width = 4ft
Length = 6ft
Circumference=2pir=<span>2∗3.14∗5.1</span><span>=30.028=30.03.</span>