x = number of desks needed to make
equation: 150 +15.50x >= 400
solution:
150 +15.50x >=400
15.50x = 250
x = 250/15.50 = 16.129
he needs to assemble 17 desks
15.50*17 = 263.50 +150 = $413.50
Yes it is the answer that is last on the list because it is that answer
<u>Given</u>:
The given equation is 
We need to determine the exact solutions of the equation.
<u>Exact solution:</u>
The exact solution of the equation can be determined by solving the equation using quadratic formula,
From the equation the values are a = 1, b = -3 and c = -7
Thus, substituting these values in the equation, we get;
Thus, the exact solutions of the given equation is
Hence, Option A is the correct answer.
It's difficult to make out what the force and displacement vectors are supposed to be, so I'll generalize.
Let <em>θ</em> be the angle between the force vector <em>F</em> and the displacement vector <em>r</em>. The work <em>W</em> done by <em>F</em> in the direction of <em>r</em> is
<em>W</em> = <em>F</em> • <em>r</em> cos(<em>θ</em>)
The cosine of the angle between the vectors can be obtained from the dot product identity,
<em>a</em> • <em>b</em> = ||<em>a</em>|| ||<em>b</em>|| cos(<em>θ</em>) ==> cos(<em>θ</em>) = (<em>a</em> • <em>b</em>) / (||<em>a</em>|| ||<em>b</em>||)
so that
<em>W</em> = (<em>F</em> • <em>r</em>)² / (||<em>F</em>|| ||<em>r</em>||)
For instance, if <em>F</em> = 3<em>i</em> + <em>j</em> + <em>k</em> and <em>r</em> = 7<em>i</em> - 7<em>j</em> - <em>k</em> (which is my closest guess to the given vectors' components), then the work done by <em>F</em> along <em>r</em> is
<em>W</em> = ((3<em>i</em> + <em>j</em> + <em>k</em>) • (7<em>i</em> - 7<em>j</em> - <em>k</em>))² / (√(3² + 1² + 1²) √(7² + (-7)² + (-1)²))
==> <em>W</em> ≈ 5.12 J
(assuming <em>F</em> and <em>r</em> are measured in Newtons (N) and meters (m), respectively).
4-3=1 and 5-4= 1 so it's 4
