A

9000024106

Level: 
A
Identify the optimal first step to solve the following equation. The operation is intended to be used on both sides of the equation. Assume \(x\neq 1\) and \(x\neq 2\). \[ \frac{1} {x - 1} = \frac{2} {x - 2} \]
multiply by \((x - 1)\cdot (x - 2)\)
multiply by \((x - 1)\)
multiply by \((x - 2)\)
multiply by \((x + 1)\)
multiply by \((x + 2)\)
multiply by \((x - 1)\cdot (x + 2)\)

9000024109

Level: 
A
Identify the optimal first step to solve the following equation. The operation is intended to be used on both sides of the equation. \[ \frac{2x + 1} {x - 1} + \frac{x + 1} {x - 1} = \frac{11} {2} \]
multiply by \(2(x - 1)\), assuming \(x\neq 1\)
multiply by \((2x + 1)\), assuming \(x\neq -\frac{1} {2}\)
multiply by \((x + 1)\), assuming \(x\neq - 1\)
multiply by \(\frac{1} {2x+1}\), assuming \(x\neq -\frac{1} {2}\)
multiply by \(\frac{1} {x+1}\), assuming \(x\neq - 1\)
multiply by \(2(2x + 1)(x + 1)\), assuming \(x\neq -\frac{1} {2}\) and \(x\neq - 1\)

9000024802

Level: 
A
Consider the equation \[ \sqrt{x^{2 } - 2x + 1} = x + 2 \] and the equation which arises from this equation by squaring both sides of the equation, i.e. the equation \[ \left (\sqrt{x^{2 } - 2x + 1}\right )^{2} = (x + 2)^{2}. \] Identify a true statement.
Both equations are equivalent only if \(x\geq - 2\).
Both equations are equivalent.
Both equations are equivalent only if \(x\leq - 2\).
None of the above.

9000024803

Level: 
A
Removing radical in an equation by squaring both sides may enrich the set of solutions of this equation and checking the solutions of the new equation in the original equation may be necessary. Identify a correct conclusion in the particular case of the following equation. \[ -\sqrt{x^{2 } - 2x + 1} = x \]
If we look for the solution in the set \(\mathbb{R}^{-}\), then squaring both sides of the equation gives an equivalent equation. The checking of the solution is not necessary.
If we look for the solution in the set \(\mathbb{R}^{+}\), then squaring both sides of the equation gives an equivalent equation. The checking of the solution is not necessary.
If we look for the solution in the set \(\mathbb{R}\), then squaring both sides of the equation gives an equivalent equation. The checking of the solution is not necessary.
None of the above.

9000024101

Level: 
A
Identify the optimal first step to solve the following equation. The operation is intended to be used on both sides of the equation. \[ 3x + 2 = -5x + 1 \]
add \((5x - 2)\)
multiply by \(\frac{1} {3}\)
multiply by \(-\frac{1} {5}\)
add \((-3x + 2)\)
add \((5x + 1)\)
add \((3x - 1)\)

9000022305

Level: 
A
Find the domain of the following expression. \[ \sqrt{-x^{2 } + 16x - 63} \]
\(\left [ 7;9\right ] \)
\(\left (-\infty ;7\right )\cup \left (9;\infty \right )\)
\(\left (-\infty ;-7\right ] \cup \left [ 9;\infty \right )\)
\(\left (7;9\right )\)
\(\left [ -7;9\right ] \)