Solving an equation via substitution to reduce to quadratic form
The question presents an equation involving radicals, rational expressions, or other non-polynomial terms that requires a substitution (e.g., u = √x, u = x - y) to transform it into a standard quadratic equation to solve.
What is the sum of all real roots of the equation $\sqrt { x ^ { 2 } - 2 x + 1 } - \sqrt { x ^ { 2 } - 2 x } = \frac { 1 } { 2 }$? [3 points] (1) 5 (2) 4 (3) 3 (4) 2 (5) 1
Find the product of all real roots of the irrational equation $\sqrt { 2 x ^ { 2 } - 6 x } = x ^ { 2 } - 3 x - 4$, and call it $k$. Find the value of $k ^ { 2 }$. [3 points]
For the irrational equation $x ^ { 2 } - 6 x - \sqrt { x ^ { 2 } - 6 x - 1 } = 3$, let $k$ be the product of all real roots. Find the value of $k ^ { 2 }$. [3 points]
The equation $\sqrt { 3 x ^ { 2 } + x + 5 } = x - 3$, where $x$ is real, has (1) no solution (2) exactly four solutions (3) exactly one solution (4) exactly two solutions
The number of solutions of the equation $\left(\frac{9}{x} - \frac{9}{\sqrt{x}} + 2\right)\left(\frac{2}{x} - \frac{7}{\sqrt{x}} + 3\right) = 0$ is: (1) 2 (2) 3 (3) 1 (4) 4