# pre calc

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find exact solution algebraically and check it by substituting into the original equation.

2(10^-x/3)=20

logtiny4(x-5)=-1

• pre calc -

you probably meant:
2(10^-(x/3) )=20
10^(-x/3) = 10 = 10^1 , now you have the same bases, so
-x/3 = 1
x = -3

log4 (x-5) = -1
by definition:
x-5 = 4^-1
x-5 = 1/4 = .25
x = 5.25
x = 1029

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