Question 609079
log(14x+45)-log 7=log 2-log x
log((14x+45)/7) = log 2-log x
log((14x+45)/7) = log(2/x)
(14x+45)/7 = 2/x
cross-multiply:
x(14x+45) = 7*2
14x^2+45x = 49
14x^2+45x-49 = 0
solving for x by using the quadratic formula yields:
x = {0.86, -4.1}
we can throw out the negative solution (extraneous) leaving:
x = 0.86
.
Details of quadratic formula:
*[invoke quadratic "x", 14, 45, -49 ]