Answer:
x = - 4
Step-by-step explanation:
Answer:
$8.40
Step-by-step explanation:
to find discount you use part=%(whole) so you are looking for your part but know the % and whole so you do x=40%(21) and 40%, or 0.4, times 21 is 8.4 so thats your part, 8.4 is 40% of 21 and thats how much youll pay
This is a function, imagine if there were a line going up and down through every point, if one of those lines hits 2 points then it's not a function
let's first off apply a log rule of cancellation, keeping in mind that, first off is ln(), not in(), and that ln() is just a shortcut to logₑ.
![\bf \textit{Logarithm Cancellation Rules} \\\\ log_a a^x = x\qquad \qquad \stackrel{\stackrel{\textit{we'll use this one}}{\downarrow }}{a^{log_a x}=x} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ e^{ln(x)}\implies e^{log_e(x)}\implies x \\\\\\ \cfrac{d}{dx}\left[ e^{ln(x)} \right]\implies \cfrac{d}{dx}[x]\implies 1](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7BLogarithm%20Cancellation%20Rules%7D%0A%5C%5C%5C%5C%0Alog_a%20a%5Ex%20%3D%20x%5Cqquad%20%5Cqquad%20%5Cstackrel%7B%5Cstackrel%7B%5Ctextit%7Bwe%27ll%20use%20this%20one%7D%7D%7B%5Cdownarrow%20%7D%7D%7Ba%5E%7Blog_a%20x%7D%3Dx%7D%0A%5C%5C%5C%5C%5B-0.35em%5D%0A%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%0Ae%5E%7Bln%28x%29%7D%5Cimplies%20e%5E%7Blog_e%28x%29%7D%5Cimplies%20x%0A%5C%5C%5C%5C%5C%5C%0A%5Ccfrac%7Bd%7D%7Bdx%7D%5Cleft%5B%20e%5E%7Bln%28x%29%7D%20%5Cright%5D%5Cimplies%20%5Ccfrac%7Bd%7D%7Bdx%7D%5Bx%5D%5Cimplies%201)
