9000020010
Level:
A
Choose the equation which is obtained by squaring both
sides of the following equation.
\[
\sqrt{x^{2 } - x + 5} = 2x - 5
\]
\(3x^{2} - 19x + 20 = 0\)
\(x^{2} + 3x + 20 = 0\)
\(3x^{2} + x - 30 = 0\)
\(3x^{2} + x + 20 = 0\)
A
9000020910
Level:
A
The perimeter of a rectangle is \(28\, \mathrm{cm}\).
The diagonal of this rectangle is \(10\, \mathrm{cm}\).
Find the sides of the rectangle.
\(8\, \mathrm{cm}\)
and \(6\, \mathrm{cm}\)
\(7\, \mathrm{cm}\)
and \(7\, \mathrm{cm}\)
\(9\, \mathrm{cm}\)
and \(5\, \mathrm{cm}\)
\(7\, \mathrm{cm}\)
and \(3\, \mathrm{cm}\)
9000020401
Level:
A
Solve the following quadratic equation.
\[
-x^{2} + 12x - 20 = 0
\]
\(x_{1} = 2\),
\(x_{2} = 10\)
\(x_{1} = -2\),
\(x_{2} = 10\)
\(x_{1} = -2\),
\(x_{2} = -10\)
\(x_{1} = 2\),
\(x_{2} = -10\)
9000020906
Level:
A
Identify an equation which can be obtained from the following system by
eliminating one of the variables.
\[ \begin{alignedat}{80}
&y^{2} & - &2 &x & + &3 & = 0 & & & & & & & &
\\ &x & - & &y & - &1 & = 0 & & & & & & & &
\\\end{alignedat}\]
\((y - 1)^{2} = 0\)
\((y + 1)^{2} = 0\)
\((x - 4)^{2} = 0\)
\((x + 2)^{2} = 0\)
9000020402
Level:
A
Identify an equation which does not have real solution.
\(x^{2} - 2x + 5 = 0\)
\(x^{2} - 5 = 0\)
\(x^{2} + 0.8x = 0\)
\(- x^{2} + 2x + 35 = 0\)
9000020403
Level:
A
Identify an equation which does not have at least one solution in the interval
\((0;\infty )\).
\(x^{2} + 5x + 6 = 0\)
\(x^{2} - 2x - 3 = 0\)
\(x^{2} - 10x = 0\)
\(x^{2} - 10x + 24 = 0\)
9000020405
Level:
A
Identify an equation which does not have the set
\(K = \{ - 3;6\}\) as the
set of all solutions of this equation.
\(3x^{2} - 9x + 54 = 0\)
\(2x^{2} - 6x - 36 = 0\)
\(\frac{1}
{3}x^{2} - x - 6 = 0\)
\(- x^{2} + 3x + 18 = 0\)
9000020407
Level:
A
In the following list identify an equation with real solution.
\(- 0.5x^{2} + 2x + 3 = 0\)
\(- x^{2} + 4x - 5 = 0\)
\(2x^{2} - 3x + 3 = 0\)
\(x^{2} - x + 1 = 0\)
9000020408
Level:
A
Which of the given equations have at least one root the same?
\[ \begin{aligned}
x^{2} + 8x + 15 & = 0 &\text{(1)}
\\x^{2} - 8x + 15 & = 0 &\text{(2)}
\\x^{2} +\phantom{ 8}x - 12 & = 0 &\text{(3)}
\\x^{2} - 2x -\phantom{ 1}8 & = 0 &\text{(4)}
\\\end{aligned}\]
equations (2) and (3)
equations (1) and (3)
equations (2) and (4)
Such a pair does not exist.
9000020404
Level:
A
Find a number which is a sum of one half of the bigger solution of
\[
x^{2} - 10x + 24 = 0
\]
and a double of the smaller solution of
\[
-x^{2} + 10x - 16 = 0.
\]
\(7\)
\(12\)
\(6\)
\(14\)