Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-6x^2-8=-4x^2-8\)
- \(5x^2+94=9x^2-6\)
- \(-8x^2+5=-5x^2+5\)
- \(-x^2+100=0\)
- \(-2(-10x^2+7)=-(-14x^2+14)\)
- \(-x^2+16=0\)
- \(-2x^2-8=4x^2-8\)
- \(3(6x^2-8)=-(-15x^2-339)\)
- \(x^2+144=0\)
- \(-2(-9x^2+10)=-(-14x^2+20)\)
- \(-2(8x^2-8)=-(19x^2-28)\)
- \(-x^2+518=7x^2+6\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-6x^2-8=-4x^2-8 \\ \Leftrightarrow -6x^2+4x^2=-8+8 \\
\Leftrightarrow -2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2+94=9x^2-6 \\ \Leftrightarrow 5x^2-9x^2=-6-94 \\
\Leftrightarrow -4x^2 = -100 \\
\Leftrightarrow x^2 = \frac{-100}{-4}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-8x^2+5=-5x^2+5 \\ \Leftrightarrow -8x^2+5x^2=5-5 \\
\Leftrightarrow -3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-x^2+100=0 \\
\Leftrightarrow -x^2 = -100 \\
\Leftrightarrow x^2 = \frac{-100}{-1}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-2(-10x^2+7)=-(-14x^2+14) \\ \Leftrightarrow 20x^2-14=14x^2-14 \\
\Leftrightarrow 20x^2-14x^2=-14+14 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-x^2+16=0 \\
\Leftrightarrow -x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{-1}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-2x^2-8=4x^2-8 \\ \Leftrightarrow -2x^2-4x^2=-8+8 \\
\Leftrightarrow -6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(3(6x^2-8)=-(-15x^2-339) \\ \Leftrightarrow 18x^2-24=15x^2+339 \\
\Leftrightarrow 18x^2-15x^2=339+24 \\
\Leftrightarrow 3x^2 = 363 \\
\Leftrightarrow x^2 = \frac{363}{3}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(x^2+144=0 \\
\Leftrightarrow x^2 = -144 \\
\Leftrightarrow x^2 = \frac{-144}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(-9x^2+10)=-(-14x^2+20) \\ \Leftrightarrow 18x^2-20=14x^2-20 \\
\Leftrightarrow 18x^2-14x^2=-20+20 \\
\Leftrightarrow 4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(8x^2-8)=-(19x^2-28) \\ \Leftrightarrow -16x^2+16=-19x^2+28 \\
\Leftrightarrow -16x^2+19x^2=28-16 \\
\Leftrightarrow 3x^2 = 12 \\
\Leftrightarrow x^2 = \frac{12}{3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-x^2+518=7x^2+6 \\ \Leftrightarrow -x^2-7x^2=6-518 \\
\Leftrightarrow -8x^2 = -512 \\
\Leftrightarrow x^2 = \frac{-512}{-8}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)