Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(2x^2+5)=-(0x^2-586)\)
- \(-2x^2+409=3x^2+4\)
- \(-10x^2-3=-2x^2-3\)
- \(3(6x^2+8)=-(-17x^2-24)\)
- \(8x^2-1800=0\)
- \(8x^2-1355=2x^2-5\)
- \(-3(6x^2+9)=-(16x^2-45)\)
- \(7x^2-112=0\)
- \(-8x^2+1152=0\)
- \(-2(-5x^2-10)=-(-3x^2-83)\)
- \(-10x^2+120=-3x^2+8\)
- \(6x^2+0=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(2x^2+5)=-(0x^2-586) \\ \Leftrightarrow 4x^2+10=0x^2+586 \\
\Leftrightarrow 4x^2+0x^2=586-10 \\
\Leftrightarrow 4x^2 = 576 \\
\Leftrightarrow x^2 = \frac{576}{4}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-2x^2+409=3x^2+4 \\ \Leftrightarrow -2x^2-3x^2=4-409 \\
\Leftrightarrow -5x^2 = -405 \\
\Leftrightarrow x^2 = \frac{-405}{-5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-10x^2-3=-2x^2-3 \\ \Leftrightarrow -10x^2+2x^2=-3+3 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(3(6x^2+8)=-(-17x^2-24) \\ \Leftrightarrow 18x^2+24=17x^2+24 \\
\Leftrightarrow 18x^2-17x^2=24-24 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(8x^2-1800=0 \\
\Leftrightarrow 8x^2 = 1800 \\
\Leftrightarrow x^2 = \frac{1800}{8}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(8x^2-1355=2x^2-5 \\ \Leftrightarrow 8x^2-2x^2=-5+1355 \\
\Leftrightarrow 6x^2 = 1350 \\
\Leftrightarrow x^2 = \frac{1350}{6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-3(6x^2+9)=-(16x^2-45) \\ \Leftrightarrow -18x^2-27=-16x^2+45 \\
\Leftrightarrow -18x^2+16x^2=45+27 \\
\Leftrightarrow -2x^2 = 72 \\
\Leftrightarrow x^2 = \frac{72}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2-112=0 \\
\Leftrightarrow 7x^2 = 112 \\
\Leftrightarrow x^2 = \frac{112}{7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-8x^2+1152=0 \\
\Leftrightarrow -8x^2 = -1152 \\
\Leftrightarrow x^2 = \frac{-1152}{-8}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-2(-5x^2-10)=-(-3x^2-83) \\ \Leftrightarrow 10x^2+20=3x^2+83 \\
\Leftrightarrow 10x^2-3x^2=83-20 \\
\Leftrightarrow 7x^2 = 63 \\
\Leftrightarrow x^2 = \frac{63}{7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-10x^2+120=-3x^2+8 \\ \Leftrightarrow -10x^2+3x^2=8-120 \\
\Leftrightarrow -7x^2 = -112 \\
\Leftrightarrow x^2 = \frac{-112}{-7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(6x^2+0=0 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)