Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-8x^2-648=0\)
- \(-8x^2+800=0\)
- \(-8x^2+0=0\)
- \(-2(-9x^2+3)=-(-14x^2-478)\)
- \(2x^2+18=5x^2+6\)
- \(-2x^2+450=0\)
- \(-4(9x^2+5)=-(29x^2+1392)\)
- \(3(8x^2-10)=-(-19x^2-470)\)
- \(-2(-5x^2+10)=-(-16x^2+20)\)
- \(8x^2+1152=0\)
- \(2x^2-200=0\)
- \(-3(-5x^2-8)=-(-12x^2+168)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-8x^2-648=0 \\
\Leftrightarrow -8x^2 = 648 \\
\Leftrightarrow x^2 = \frac{648}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-8x^2+800=0 \\
\Leftrightarrow -8x^2 = -800 \\
\Leftrightarrow x^2 = \frac{-800}{-8}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-8x^2+0=0 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(-9x^2+3)=-(-14x^2-478) \\ \Leftrightarrow 18x^2-6=14x^2+478 \\
\Leftrightarrow 18x^2-14x^2=478+6 \\
\Leftrightarrow 4x^2 = 484 \\
\Leftrightarrow x^2 = \frac{484}{4}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(2x^2+18=5x^2+6 \\ \Leftrightarrow 2x^2-5x^2=6-18 \\
\Leftrightarrow -3x^2 = -12 \\
\Leftrightarrow x^2 = \frac{-12}{-3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-2x^2+450=0 \\
\Leftrightarrow -2x^2 = -450 \\
\Leftrightarrow x^2 = \frac{-450}{-2}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-4(9x^2+5)=-(29x^2+1392) \\ \Leftrightarrow -36x^2-20=-29x^2-1392 \\
\Leftrightarrow -36x^2+29x^2=-1392+20 \\
\Leftrightarrow -7x^2 = -1372 \\
\Leftrightarrow x^2 = \frac{-1372}{-7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(3(8x^2-10)=-(-19x^2-470) \\ \Leftrightarrow 24x^2-30=19x^2+470 \\
\Leftrightarrow 24x^2-19x^2=470+30 \\
\Leftrightarrow 5x^2 = 500 \\
\Leftrightarrow x^2 = \frac{500}{5}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-2(-5x^2+10)=-(-16x^2+20) \\ \Leftrightarrow 10x^2-20=16x^2-20 \\
\Leftrightarrow 10x^2-16x^2=-20+20 \\
\Leftrightarrow -6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(8x^2+1152=0 \\
\Leftrightarrow 8x^2 = -1152 \\
\Leftrightarrow x^2 = \frac{-1152}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2-200=0 \\
\Leftrightarrow 2x^2 = 200 \\
\Leftrightarrow x^2 = \frac{200}{2}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-3(-5x^2-8)=-(-12x^2+168) \\ \Leftrightarrow 15x^2+24=12x^2-168 \\
\Leftrightarrow 15x^2-12x^2=-168-24 \\
\Leftrightarrow 3x^2 = -192 \\
\Leftrightarrow x^2 = \frac{-192}{3} < 0 \\
V = \varnothing \\ -----------------\)