271.
1) log3_(2x-1) = 2;
2x-1 = 3^2;
2x-1 = 9;
2x = 10;
x =5;
2) ln(3x-5) = 0;
ln(3x - 5) =ln 1;
3x - 5 = 1;
3x = 6;
x = 2.
3) log7_(4 - x) = 1;
4 - x = 7^1;
- x = 7 - 4;
x = - 3.
4) lg(2x - 1) = lg 3;
2x - 1 = 3;
2x = 4;
x = 2.
273.
1) lg(x(5 - x)) = lg 4;
5x - x^2 = 4;
x^2 - 5x + 4 = 0;
x1 = 1;
x2 = 4.
2) lg(x(x-1)) = lg 2;
x^2 - x = 2;
x^2 - x - 2 = 0;
x1 = -1; не подходит, так как по одз x > 0
x2 = 2.
3) ln(x(6-x)) = ln 5;
6x - x^2 = 5;
x^2 - 6x + 5 = 0;
x1 = 1;
x2 = 5.
4) 4 - x = 1 - 2x;
- x + 2x = 1 - 4;
x = - 3