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Common Core Alignment ![]() |
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#1 |
Join Date: Sep 2009
Posts: 1
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![]() I have three questions that I don't get how to complete/start in a math assignment during the logarithm/exponent unit:
here are the three questions (image link) http://img3.imageshack.us/img3/4051/mathassignment.png please message back if you can help with them ![]() |
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#2 | |
![]() ![]() ![]() Join Date: Dec 2008
Posts: 249
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![]() Quote:
a^(3x/2) = (a^(x^2))(a^(-(5/7)-(2x/7))) a^(3x/2) = a^(x^2 -(2/7)x -(5/7)) (3/2)x = x^2 -(2/7)x -(5/7) 0 = x^2 -(25/14)x -(5/7) Use quadratic formula to find x = 2.12 or -0.34 2. 2^(-1) = log9(logx(1/343)) (1/2) = log9(logx(1/343)) 9^(1/2) = logx(1/343) 3 = logx(1/343) x^3 = (1/343) x = (1/7) Note: The sqrt(9) = +3 and -3, but we cannot use -3 because it gives us x = 7 and if we plug it back into the original equation then we get log9(-3) which is not defined. 3. I'm not sure about this one. |
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#3 | |
Join Date: Aug 2009
Posts: 3
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![]() Quote:
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#4 |
![]() ![]() ![]() ![]() ![]() ![]() Join Date: Feb 2010
Posts: 388
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![]() 1. (sqrt(a))^3x = (a^(x^2))((a^(1/7))^(-5-2x))
a^(3x/2) = (a^(x^2))(a^(-(5/7)-(2x/7))) a^(3x/2) = a^(x^2 -(2/7)x -(5/7)) (3/2)x = x^2 -(2/7)x -(5/7) 0 = x^2 -(25/14)x -(5/7) . 2^(-1) = log9(logx(1/343)) (1/2) = log9(logx(1/343)) 9^(1/2) = logx(1/343) 3 = logx(1/343) x^3 = (1/343) x = (1/7) |
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