Only problem is with the simplifying.
We all know that 5/5 = 1, it is natural to assume (x+a)/(x+a) is also 1, but in some cases where x+a=0, it is undefined. In this equation, where they simplify (x-2) and (x-6), you must say that x is not 2 nor 6 or, you just delete 0/0 which is undefined.
Therefore the only solution would be x=-1
The elephant that weighs 2.85 tons
<span>y=
-0.000475x^2 + 0.851x
How high above is the
river bridge (the top of the arch)?
You have to find the vertex of of the parabole: the y-coordinate is the highest point.
Remember that the x-coordinate of the vertex of a parabole is at - b / 2a.
That is x = - 0.851 / [ 2(-0.000475) = 895.79
The corresponden y is y = </span><span>-0.000475(895.79)^2 + 0.851(895.79) = 381.16 feet above the river.
How long is section of bridge above
the arch?
The section of the brige is equal to the difference of the two roots
Roots: </span><span>y=
-0.000475x^2 + 0.851x = 0
=> x( - 0.000475x + 0.851) = 0
=> x = 0 and x = 0.851 / 0.000475 = 1791.58
Then the section is 1791.58 feet long.
Therefore, the answer is the option </span><span>D)The bridge is about 381.16 ft. above the river, and the length of the bridge above the arch is about 1,791.58 ft
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