Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(x^2+26=8x^2-2\)
- \(5(-7x^2+6)=-(27x^2+170)\)
- \(5x^2+500=0\)
- \(5x^2+125=0\)
- \(2x^2-5=-5x^2-5\)
- \(4x^2-784=0\)
- \(5(-6x^2+4)=-(34x^2+236)\)
- \(-4(10x^2+8)=-(41x^2+228)\)
- \(-6x^2-216=0\)
- \(3(-3x^2+2)=-(13x^2-70)\)
- \(-2x^2+2=0\)
- \(5x^2-405=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(x^2+26=8x^2-2 \\ \Leftrightarrow x^2-8x^2=-2-26 \\
\Leftrightarrow -7x^2 = -28 \\
\Leftrightarrow x^2 = \frac{-28}{-7}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(5(-7x^2+6)=-(27x^2+170) \\ \Leftrightarrow -35x^2+30=-27x^2-170 \\
\Leftrightarrow -35x^2+27x^2=-170-30 \\
\Leftrightarrow -8x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{-8}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(5x^2+500=0 \\
\Leftrightarrow 5x^2 = -500 \\
\Leftrightarrow x^2 = \frac{-500}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+125=0 \\
\Leftrightarrow 5x^2 = -125 \\
\Leftrightarrow x^2 = \frac{-125}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2-5=-5x^2-5 \\ \Leftrightarrow 2x^2+5x^2=-5+5 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4x^2-784=0 \\
\Leftrightarrow 4x^2 = 784 \\
\Leftrightarrow x^2 = \frac{784}{4}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(5(-6x^2+4)=-(34x^2+236) \\ \Leftrightarrow -30x^2+20=-34x^2-236 \\
\Leftrightarrow -30x^2+34x^2=-236-20 \\
\Leftrightarrow 4x^2 = -256 \\
\Leftrightarrow x^2 = \frac{-256}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(10x^2+8)=-(41x^2+228) \\ \Leftrightarrow -40x^2-32=-41x^2-228 \\
\Leftrightarrow -40x^2+41x^2=-228+32 \\
\Leftrightarrow x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-6x^2-216=0 \\
\Leftrightarrow -6x^2 = 216 \\
\Leftrightarrow x^2 = \frac{216}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(-3x^2+2)=-(13x^2-70) \\ \Leftrightarrow -9x^2+6=-13x^2+70 \\
\Leftrightarrow -9x^2+13x^2=70-6 \\
\Leftrightarrow 4x^2 = 64 \\
\Leftrightarrow x^2 = \frac{64}{4}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-2x^2+2=0 \\
\Leftrightarrow -2x^2 = -2 \\
\Leftrightarrow x^2 = \frac{-2}{-2}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(5x^2-405=0 \\
\Leftrightarrow 5x^2 = 405 \\
\Leftrightarrow x^2 = \frac{405}{5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)