Answer:
Step-by-step explanation:
The question in English is
In one appliance store, a refrigerator cost $8,900 and they lowered it to $7,120. What percentage did they lower?
we know that
$8,900 ------> represent the 100%
so
by proportion
therefore
the percentage is equal to
Both expression have the same denominator: 9x²-1. Thus it must not be 0.
9x²-1=(3x-1)(3x+1)=0, resulting x=+-1/3.
Restrictions: x in R\{-1/3, 1/3}
Adding those expressions:
E=(-x-2)/(9x²-1 ) + (-5x+4)/(9x²-1)=
(-x-2-5x+4)/(9x²-1)=(-6x+2)/(9x²-1)=
(-2)(3x-1)/(9x²-1)=-2/(3x+1)
E=-2/(3x+1)
Answer:
the vertex is (-4,2), I hope this helps :)
Step-by-step explanation:
