a) (0.75)10^1.25x = 11.25

b) 3.2e^-0.5 = 0.04e^3j

c) 164.9 =log square root 2 pie R

d) log 20 + log(6x-20) = 3

e) log(x-3) = 1/2 log(12-8x)

can someone please help me with these promlems asap. Thanks

- Mar 13th 2008, 06:53 AMsara555Solving equations using calculator - Exponential/Logarithmic eq
a) (0.75)10^1.25x = 11.25

b) 3.2e^-0.5 = 0.04e^3j

c) 164.9 =log square root 2 pie R

d) log 20 + log(6x-20) = 3

e) log(x-3) = 1/2 log(12-8x)

can someone please help me with these promlems asap. Thanks - Mar 13th 2008, 07:25 AMcolby2152
$\displaystyle (0.75)10^{1.25x} = 11.25$

Divide both sides by 0.75

$\displaystyle 10^{1.25x} = \frac{11.25}{0.75} \Rightarrow 15$

Take the natural log of both sides

$\displaystyle \ln|10|1.25x = \ln|15|$

$\displaystyle 2.303*1.25x = 2.708$

$\displaystyle x = 0.940855566$