Math
posted by Eric on .
Find the exact solution, using common logarithms, and a twodecimalplace approximation of each solution.
log(7x + 4) = 2 + log(2x − 3)
Solve the equation.
log(x^3) = (log x)^2

log(7x + 4) = 2 + log(2x − 3)
log(7x + 4)  log(2x − 3) = 2
log( (7x+4)/(2x3) ) = 2
(7x+4)/(2x3) = 10^2 = 100
200x  300 = 7x+4
193x = 304
x = 304/193 or appr 1.575
for the 2nd
log x^3 = log x^2
x^3 = x^2
x^3  x^2 = 0
x^2(x1) = 0
x = 0 or x = 1
but from log(2x3) , 2x3 > 0
2x > 3
x > 3/2
so there is not solution.