C3 HelpWatch

Thread starter 9 years ago
#1
Can anyone help me? This is where I'm at. I've got 2 simulatneous equations:

ln 45= ln c -dln 49
ln 35= ln c -dln 81

And I have to show d= ln 45 - ln 35 / ln 81 - ln 49

Can anyone help? I get stuck after I decide to eliminate the ln c's.
0
9 years ago
#2
Take equation 2 away from equation 1 and make d the subject.
Thread starter 9 years ago
#3
(Original post by Lover's Knot)
Take equation 2 away from equation 1 and make d the subject.
Yeah I know that, but I can't get it
0
Thread starter 9 years ago
#4
I got it Made a couple of clumsy errors. It then says use the laws of logarithims to show d = 1/2. How do I do that?
0
9 years ago
#5
(Original post by V1NY)
I got it Made a couple of clumsy errors. It then says use the laws of logarithims to show d = 1/2. How do I do that?
d = (ln 45 - ln 35) / (ln 81 - ln 49)
=> (ln(45/35)) / (ln (81/49))
=> (ln(9/7)) / (ln (9^2/7^2))
=> (ln(9/7)) / [2(ln (9/7))]
=> 1/2
Thread starter 9 years ago
#6
(Original post by Lover's Knot)
d = (ln 45 - ln 35) / (ln 81 - ln 49)
=> (ln(45/35)) / (ln (81/49))
=> (ln(9/7)) / (ln (9^2/7^2))
=> (ln(9/7)) / [2(ln (9/7))]
=> 1/2
You are awesome I'd rep you if I could.
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