Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(8x^2-57=2x^2-3\)
- \(5(-4x^2-3)=-(13x^2+22)\)
- \(7x^2+2=4x^2-10\)
- \(3(9x^2+6)=-(-22x^2-23)\)
- \(-5(4x^2+9)=-(17x^2+408)\)
- \(6x^2-600=0\)
- \(14x^2+11=8x^2+5\)
- \(-13x^2-18=-10x^2+9\)
- \(-5(-9x^2-6)=-(-42x^2+645)\)
- \(-4(9x^2+8)=-(31x^2+32)\)
- \(x^2-1=0\)
- \(2x^2-2=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(8x^2-57=2x^2-3 \\ \Leftrightarrow 8x^2-2x^2=-3+57 \\
\Leftrightarrow 6x^2 = 54 \\
\Leftrightarrow x^2 = \frac{54}{6}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(5(-4x^2-3)=-(13x^2+22) \\ \Leftrightarrow -20x^2-15=-13x^2-22 \\
\Leftrightarrow -20x^2+13x^2=-22+15 \\
\Leftrightarrow -7x^2 = -7 \\
\Leftrightarrow x^2 = \frac{-7}{-7}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(7x^2+2=4x^2-10 \\ \Leftrightarrow 7x^2-4x^2=-10-2 \\
\Leftrightarrow 3x^2 = -12 \\
\Leftrightarrow x^2 = \frac{-12}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(9x^2+6)=-(-22x^2-23) \\ \Leftrightarrow 27x^2+18=22x^2+23 \\
\Leftrightarrow 27x^2-22x^2=23-18 \\
\Leftrightarrow 5x^2 = 5 \\
\Leftrightarrow x^2 = \frac{5}{5}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-5(4x^2+9)=-(17x^2+408) \\ \Leftrightarrow -20x^2-45=-17x^2-408 \\
\Leftrightarrow -20x^2+17x^2=-408+45 \\
\Leftrightarrow -3x^2 = -363 \\
\Leftrightarrow x^2 = \frac{-363}{-3}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(6x^2-600=0 \\
\Leftrightarrow 6x^2 = 600 \\
\Leftrightarrow x^2 = \frac{600}{6}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(14x^2+11=8x^2+5 \\ \Leftrightarrow 14x^2-8x^2=5-11 \\
\Leftrightarrow 6x^2 = -6 \\
\Leftrightarrow x^2 = \frac{-6}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-13x^2-18=-10x^2+9 \\ \Leftrightarrow -13x^2+10x^2=9+18 \\
\Leftrightarrow -3x^2 = 27 \\
\Leftrightarrow x^2 = \frac{27}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(-9x^2-6)=-(-42x^2+645) \\ \Leftrightarrow 45x^2+30=42x^2-645 \\
\Leftrightarrow 45x^2-42x^2=-645-30 \\
\Leftrightarrow 3x^2 = -675 \\
\Leftrightarrow x^2 = \frac{-675}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(9x^2+8)=-(31x^2+32) \\ \Leftrightarrow -36x^2-32=-31x^2-32 \\
\Leftrightarrow -36x^2+31x^2=-32+32 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-1=0 \\
\Leftrightarrow x^2 = 1 \\
\Leftrightarrow x^2 = \frac{1}{1}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(2x^2-2=0 \\
\Leftrightarrow 2x^2 = 2 \\
\Leftrightarrow x^2 = \frac{2}{2}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)