Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-6x^2-726=0\)
- \(-8x^2-648=0\)
- \(2x^2+242=0\)
- \(5(6x^2-6)=-(-35x^2+30)\)
- \(4x^2+870=-2x^2+6\)
- \(9x^2-8=5x^2-8\)
- \(-8x^2+288=0\)
- \(2x^2-32=0\)
- \(3x^2-48=0\)
- \(x^2-254=5x^2+2\)
- \(-5x^2-125=0\)
- \(2(10x^2-10)=-(-15x^2-700)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-6x^2-726=0 \\
\Leftrightarrow -6x^2 = 726 \\
\Leftrightarrow x^2 = \frac{726}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-8x^2-648=0 \\
\Leftrightarrow -8x^2 = 648 \\
\Leftrightarrow x^2 = \frac{648}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+242=0 \\
\Leftrightarrow 2x^2 = -242 \\
\Leftrightarrow x^2 = \frac{-242}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(5(6x^2-6)=-(-35x^2+30) \\ \Leftrightarrow 30x^2-30=35x^2-30 \\
\Leftrightarrow 30x^2-35x^2=-30+30 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4x^2+870=-2x^2+6 \\ \Leftrightarrow 4x^2+2x^2=6-870 \\
\Leftrightarrow 6x^2 = -864 \\
\Leftrightarrow x^2 = \frac{-864}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(9x^2-8=5x^2-8 \\ \Leftrightarrow 9x^2-5x^2=-8+8 \\
\Leftrightarrow 4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-8x^2+288=0 \\
\Leftrightarrow -8x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{-8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(2x^2-32=0 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(3x^2-48=0 \\
\Leftrightarrow 3x^2 = 48 \\
\Leftrightarrow x^2 = \frac{48}{3}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(x^2-254=5x^2+2 \\ \Leftrightarrow x^2-5x^2=2+254 \\
\Leftrightarrow -4x^2 = 256 \\
\Leftrightarrow x^2 = \frac{256}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2-125=0 \\
\Leftrightarrow -5x^2 = 125 \\
\Leftrightarrow x^2 = \frac{125}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(10x^2-10)=-(-15x^2-700) \\ \Leftrightarrow 20x^2-20=15x^2+700 \\
\Leftrightarrow 20x^2-15x^2=700+20 \\
\Leftrightarrow 5x^2 = 720 \\
\Leftrightarrow x^2 = \frac{720}{5}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)