When you're out shopping and something you want to buy is on sale. You can take the original price and give it's percentage to find out how much it really is.
First, we need to transform the equation into its standard form (x - h)²=4p(y - k).
Using completing the square method:
y = -14x² - 2x - 2
y = -14(x² + 2x/14) - 2
y = -14(x² + 2x/14 + (2/28)²) -2 + (2/28)²
y = -14(x + 1/14)² - 391/196
-1/14(y + 391/196) = (x + 1/14)²
This is a vertical parabola and its focus <span>(h, k + p) is (-1/14, -391/196 + 1/56) = (-1/14, -775/392).
Or (-0.071,-1.977).</span>
Answer:
%35 of them were in color
Step-by-step explanation:
Since 30 percent of the first 200 sold were in color, 200x30/100 = 60 of them were in color.
Since 20 percent of the next 300 sold were in color, 300x20/100 = 60 of them were in color.
Since 90 percent of the last 100 sold were in color, 100x90/100 = 90 of them were in color.
In total, 60 + 60 + 90 = 210 out of 600 were in color.
The percentage is:
=
→ x =
= 35