Answer:
The answer is D she paid 38,400
Step-by-step explanation:
30,000 + 8400 = 38,400
![\bf \stackrel{f(x)}{0}=-(x+9)(x-21)\implies \begin{cases} 0=-x-9\implies &x=-9\\ 0=x-21\implies &21=x \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \boxed{-9}\rule[0.35em]{8em}{0.25pt}0\rule[0.35em]{5em}{0.25pt}\stackrel{\downarrow }{6}\rule[0.35em]{10em}{0.25pt}\boxed{21}](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7Bf%28x%29%7D%7B0%7D%3D-%28x%2B9%29%28x-21%29%5Cimplies%20%5Cbegin%7Bcases%7D%200%3D-x-9%5Cimplies%20%26x%3D-9%5C%5C%200%3Dx-21%5Cimplies%20%2621%3Dx%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cboxed%7B-9%7D%5Crule%5B0.35em%5D%7B8em%7D%7B0.25pt%7D0%5Crule%5B0.35em%5D%7B5em%7D%7B0.25pt%7D%5Cstackrel%7B%5Cdownarrow%20%7D%7B6%7D%5Crule%5B0.35em%5D%7B10em%7D%7B0.25pt%7D%5Cboxed%7B21%7D)
now, this parabolic graph, has two zeros/solutions/x-intercepts, at -9 and 21.
for a quadratic equation, the vertex will be right in between the x-intercepts, namely in this case between -9 and 21, right in the middle, namely at 6, and is where the axis of symmetry is at, x = 6.
Lifting a piece of furniture and moving it to the right. Since all of the forces aren't going the same direction, no work is being done.
Answer:
Zero-elevation surface is a vertical datum that is used to describe a surface, such as that of a planet. The value of this datum is usually adopted by statute. This elevation is used, for example, to build a texture map from an agreed surface, such as a spheroid with dimensions defined by a mean surface gravity.
Step-by-step explanation:
