Friday,+February+5,+2010Set6

Worksheet:

1. Gilad A=1/2 5=1/2B B=10 f(x) = 1/2*10(to the power of)x 2. Cooper 3. Sam H

4. Jack - a) b) c) d) e) 269,910(.039)=10526.49 y= -10526.49x+269,910 200,000=-10526.49x+269,910 -69,910= -10526.49x x= 6.64 years 5a. David Answer please?

5b. Ron

5c. Charlie

6a. Chris 2^2x - 2^x - 6 = 0 let q=2^x q^2 - q - 6 = 0 (q-3)(q+2) = 0 q=3 or -2

3=2^x or -2=2^x log3=log2^x log -2=log2^x log3=x log2 log -2=x log2 x=(log3)/(log2) x=(log -2)/(log2) x=1.585 x=D.N.E.

x=1.585

6b. Avi Just to be clear about Avi's answer above -- that is NOT an ordered pair; it is the set of two numbers that make the equation true! 6c. Augustine 1/2z^-4/5=8 z^-4/5=16 1/z^4/5=16 (1/z^4/5)z^4/5=(16)z^4/5 1=16z^4/5 1/16=z^4/5 2^-4=(z^1/5)^4 2^-1= z^1/5 2^-5=z Good!

6d. Sam P -x^2/3=1 x=-1 Quite a bit more work needed here. It is a quadratic equation of x raised to some power (what power?)! How do you factor that quadratic, and where do you go from there? I don't get -1 as one of the answers. 6e. Rafa 4^x = 2^(x+3) 2^2x = 2^(x+3) 2x = x+3 x = 3

6f. Sarah S.

8 ^(X+3) = (1/4) ^(3X-6) 2 ^3(X+3) = 2 ^-2(3X-6) 2 ^(3X+9) = 2 ^(-6X+12) 3X+9 = -6X+12 9X = 3 X = 1/3

6g. Julia

6h. Nate

6i. Katie And please divide this through; why leave a decimal in a fraction? Also, where should there have been paretheses in the above work? They are really integral.

6j. Becca

Again, where should there be parentheses in the above problem? x/x+1/x=1.585 1+1/x=1.585 1/x=.585 1=.585x 1/.585=x