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 Post subject: algebra question
PostPosted: Mon Nov 23, 2009 12:26 pm 
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Joined: Sat Nov 14, 2009 6:39 pm
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hi!
could someone please explain question 2 on page 7 of the algebra book? thanks!


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 Post subject: Re: algebra question
PostPosted: Sat Dec 12, 2009 3:31 pm 
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Our first goal, any time we have variables in our exponents, is to get the bases the same on both sides of the equation.

Look first at 75^y. 75 is the same as 5*5*3, so let's make it 5^5 * 5^y * 3^y. Combining the 5's gives us 5^2y. Our entire term is now 3^y * 5^2y.
27 is the same as 3^3, so we can adjust this term to become 3^(6y+3)

Now, we have 3^y * 5^2y * 3^(6y+3) on the left.
Combine the 3's and we have 3^(7y+3) * 5^2y
At this point, our bases are the same on both sides, so we know that
2y=4, which means y=2
and
7y+3 = x
Since we know that y=2, we know 7y+3 is 17, and that x=17.

Hope this helps!

Veritas Help


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