An item costs $330 before tax, and the sales tax is $19.80

Find the sales tax rate. Write your answer as a percentage

5. 66%

Step-by-step explanation:

Sales tax = $19.80

Cost of item before sales tax = $330

Cost of item after sales tax = 19.80+19.80 + 19.80+330

= $349.80

Sales tax rate

19.80349.80×100%5.66%\begin{lgathered}\frac{19.80}{349.80} \times 100\% \\ 5.66\%\end{lgathered}

349.80

19.80

×100%

5.66%

So rate of sales tax is 5.66%

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this

77

step-by-step explanation: