Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(10x^2+6)=-(-13x^2-12)\)
- \(-2(4x^2+3)=-(2x^2+300)\)
- \(11x^2+43=10x^2-6\)
- \(-8x^2+8=0\)
- \(13x^2-1121=8x^2+4\)
- \(-3(-2x^2-5)=-(-7x^2+10)\)
- \(-17x^2-262=-10x^2-10\)
- \(-4x^2+0=0\)
- \(-5x^2-45=-7x^2+5\)
- \(-6x^2+96=0\)
- \(7x^2-567=0\)
- \(-4x^2-5=-3x^2-5\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(10x^2+6)=-(-13x^2-12) \\ \Leftrightarrow 20x^2+12=13x^2+12 \\
\Leftrightarrow 20x^2-13x^2=12-12 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(4x^2+3)=-(2x^2+300) \\ \Leftrightarrow -8x^2-6=-2x^2-300 \\
\Leftrightarrow -8x^2+2x^2=-300+6 \\
\Leftrightarrow -6x^2 = -294 \\
\Leftrightarrow x^2 = \frac{-294}{-6}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(11x^2+43=10x^2-6 \\ \Leftrightarrow 11x^2-10x^2=-6-43 \\
\Leftrightarrow x^2 = -49 \\
\Leftrightarrow x^2 = \frac{-49}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-8x^2+8=0 \\
\Leftrightarrow -8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-8}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(13x^2-1121=8x^2+4 \\ \Leftrightarrow 13x^2-8x^2=4+1121 \\
\Leftrightarrow 5x^2 = 1125 \\
\Leftrightarrow x^2 = \frac{1125}{5}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-3(-2x^2-5)=-(-7x^2+10) \\ \Leftrightarrow 6x^2+15=7x^2-10 \\
\Leftrightarrow 6x^2-7x^2=-10-15 \\
\Leftrightarrow -x^2 = -25 \\
\Leftrightarrow x^2 = \frac{-25}{-1}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-17x^2-262=-10x^2-10 \\ \Leftrightarrow -17x^2+10x^2=-10+262 \\
\Leftrightarrow -7x^2 = 252 \\
\Leftrightarrow x^2 = \frac{252}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4x^2+0=0 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2-45=-7x^2+5 \\ \Leftrightarrow -5x^2+7x^2=5+45 \\
\Leftrightarrow 2x^2 = 50 \\
\Leftrightarrow x^2 = \frac{50}{2}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-6x^2+96=0 \\
\Leftrightarrow -6x^2 = -96 \\
\Leftrightarrow x^2 = \frac{-96}{-6}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(7x^2-567=0 \\
\Leftrightarrow 7x^2 = 567 \\
\Leftrightarrow x^2 = \frac{567}{7}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-4x^2-5=-3x^2-5 \\ \Leftrightarrow -4x^2+3x^2=-5+5 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)