18 (goes down): 17, 16, 15
12 (goes up): 13, 14, 15
The shortest height at which the two stacks of boxes will be the same height is 15.
Hope I was able to help!
The sum of n terms is given from the first term and the common ratio by

For your given values of a1=-11, r=-4, n=8, the sum of 8 terms is

It's the last option again. You have 1 linear factor (3<em>x</em>) and 2 copies of a quadratic factor (<em>x</em>² + 10), and the partial fractions with the quadratic factor need to have a linear polynomial in the numerator.
Is there a picture or is that it
We know that the perimeter of a rectangle is 2(width)+2(length). We can multiply the length by 2 to find out how much remaining fencing we have, then divide that number by 2 to find the width.
15.5*2=31
170.5-31=139.5
139.5/2=69.75
A possible width is 69.75 feet.