Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(-2x^2+7)=-(-4x^2+35)\)
- \(-5x^2+500=0\)
- \(12x^2-22=10x^2+10\)
- \(-4(8x^2+6)=-(38x^2+750)\)
- \(-5x^2-1=-7x^2-3\)
- \(11x^2-110=4x^2+2\)
- \(7x^2+191=3x^2-5\)
- \(x^2+9=0\)
- \(3(9x^2+6)=-(-25x^2-356)\)
- \(-3(-7x^2+10)=-(-24x^2+393)\)
- \(5(-4x^2-3)=-(13x^2+8)\)
- \(-3x^2+216=-4x^2-9\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(-2x^2+7)=-(-4x^2+35) \\ \Leftrightarrow 10x^2-35=4x^2-35 \\
\Leftrightarrow 10x^2-4x^2=-35+35 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2+500=0 \\
\Leftrightarrow -5x^2 = -500 \\
\Leftrightarrow x^2 = \frac{-500}{-5}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(12x^2-22=10x^2+10 \\ \Leftrightarrow 12x^2-10x^2=10+22 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-4(8x^2+6)=-(38x^2+750) \\ \Leftrightarrow -32x^2-24=-38x^2-750 \\
\Leftrightarrow -32x^2+38x^2=-750+24 \\
\Leftrightarrow 6x^2 = -726 \\
\Leftrightarrow x^2 = \frac{-726}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2-1=-7x^2-3 \\ \Leftrightarrow -5x^2+7x^2=-3+1 \\
\Leftrightarrow 2x^2 = -2 \\
\Leftrightarrow x^2 = \frac{-2}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(11x^2-110=4x^2+2 \\ \Leftrightarrow 11x^2-4x^2=2+110 \\
\Leftrightarrow 7x^2 = 112 \\
\Leftrightarrow x^2 = \frac{112}{7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(7x^2+191=3x^2-5 \\ \Leftrightarrow 7x^2-3x^2=-5-191 \\
\Leftrightarrow 4x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2+9=0 \\
\Leftrightarrow x^2 = -9 \\
\Leftrightarrow x^2 = \frac{-9}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(9x^2+6)=-(-25x^2-356) \\ \Leftrightarrow 27x^2+18=25x^2+356 \\
\Leftrightarrow 27x^2-25x^2=356-18 \\
\Leftrightarrow 2x^2 = 338 \\
\Leftrightarrow x^2 = \frac{338}{2}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3(-7x^2+10)=-(-24x^2+393) \\ \Leftrightarrow 21x^2-30=24x^2-393 \\
\Leftrightarrow 21x^2-24x^2=-393+30 \\
\Leftrightarrow -3x^2 = -363 \\
\Leftrightarrow x^2 = \frac{-363}{-3}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(5(-4x^2-3)=-(13x^2+8) \\ \Leftrightarrow -20x^2-15=-13x^2-8 \\
\Leftrightarrow -20x^2+13x^2=-8+15 \\
\Leftrightarrow -7x^2 = 7 \\
\Leftrightarrow x^2 = \frac{7}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+216=-4x^2-9 \\ \Leftrightarrow -3x^2+4x^2=-9-216 \\
\Leftrightarrow x^2 = -225 \\
\Leftrightarrow x^2 = \frac{-225}{1} < 0 \\
V = \varnothing \\ -----------------\)