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 Posted: Tue Apr 17, 2007 7:50 pm
radical(y + 21) + radical(y) = 7
find all solutions of y.
argh, the book doesn't even have examples of this one. D:<
it's weird, because in the section it's under, we're doing that whole thing where you substitute one variable in place of another complex variable in a polynomial equation, such as (x - 35) + [radical(x - 35)] - 4 = 0, then you go y = radical(x - 35) and substitute that instead and yadayadayada.
and yeah, it doesn't exactly fit in thur D;
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Posted: Wed Apr 18, 2007 1:51 pm
radical(y + 21) + radical(y) = 7
I'm going to write rt instead of radical.
This is actually quite easy.
Take rt y to the right side so you have:
rt(y+21)=7-rt(y)
square both sides, This will eliminate the square root on the left
y+21=(7-rt(y))*(7-rt(y))
Distribute or "FOIL" the right side of the equation
y+21=49-14rt(y)+y
Take 49 and y to the left side:
-28=-14rt(y)
Divide by -14
2=rt(y)
Square both sides:
4=y
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plopperscioly_in_USSR Vice Captain
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Posted: Wed Apr 18, 2007 3:36 pm
all right... i feel dumb for not thinking of that.
but thank you. xd
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