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I am confused on numbers 25 and 29, the instructions are at the top.

I am confused on numbers 25 and 29, the instructions are at the top.-example-1

1 Answer

3 votes
#25 is fairly simple. Plug in -4 and 3 into the equation, and the extraneous root will be the one that does not work.

√(12-(-4)) = √(16) = \frac{+}{}4
Extraneous root in this case is positive four since +4≠-4

√(12-3) = √(9) = \frac{+}{}3
In this case it's negative 3, since -3≠3

#29 can be turned into a quadratic equation.

x= √(2x+3)
Square both sides to get

x^(2)=2x+3
Then bring the 2x+3 to the other side, setting the quadratic equal to zero.

x^(2)-2x-3=0
Factor to find that it's equivalent to
(x-3)(x+1)=0
Therefore x is equal to positive 3 and negative 1. Plug both back into the original equation. Whichever does not work is the extraneous root, and the answer is the one that does.

x= √(2x+3)

3= √(2(3)+3)

3= √(9)
Extraneous root would be negative 3.


-1= √(2(-1)+3)

-1= √(1)
Extraneous root would be positive 1.

Your answers are positive 3 and negative 1.
Extraneous roots are negative 3 and positive 1.
User Steve Sawyer
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