First, we'll use the power property of logarithms for the left term:
2lg x = lg(x^2)
We'll re-write the equation:
lg(x^2) = lg(3x-2)
We'll use the one to one property:
x^2 = 3x-2
We'll move all termsto the left side:
x^2 - 3x + 2 = 0
We'll use the quadratic formula:
x1 = [3+sqrt(9-8)]/2
x1 = (3+1)/2
x1 = 2
x2 = 1
We'll verify the results into equation:
2lg x1=lg(3x1 - 2)
2lg2 = lg(6-2)
lg 2^2 = lg4
lg4 = lg4
2lg x2=lg(3x2 - 2)
2lg 1=lg(3-2)
2*0 = lg 1
0 = 0
So, both values of x are the solutions of the equation:
x1 = 2 and x2 = 1
No comments:
Post a Comment