Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4x^2+484=0\)
- \(-5(2x^2-8)=-(5x^2-40)\)
- \(6x^2-33=9x^2-6\)
- \(7x^2-973=2x^2+7\)
- \(x^2-144=0\)
- \(3(-9x^2-7)=-(19x^2+53)\)
- \(4x^2+196=0\)
- \(-11x^2-50=-8x^2-2\)
- \(-3x^2-108=0\)
- \(-3(-10x^2-2)=-(-36x^2+1344)\)
- \(7x^2+0=0\)
- \(8x^2+329=10x^2-9\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4x^2+484=0 \\
\Leftrightarrow -4x^2 = -484 \\
\Leftrightarrow x^2 = \frac{-484}{-4}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-5(2x^2-8)=-(5x^2-40) \\ \Leftrightarrow -10x^2+40=-5x^2+40 \\
\Leftrightarrow -10x^2+5x^2=40-40 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(6x^2-33=9x^2-6 \\ \Leftrightarrow 6x^2-9x^2=-6+33 \\
\Leftrightarrow -3x^2 = 27 \\
\Leftrightarrow x^2 = \frac{27}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2-973=2x^2+7 \\ \Leftrightarrow 7x^2-2x^2=7+973 \\
\Leftrightarrow 5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{5}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(x^2-144=0 \\
\Leftrightarrow x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{1}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(3(-9x^2-7)=-(19x^2+53) \\ \Leftrightarrow -27x^2-21=-19x^2-53 \\
\Leftrightarrow -27x^2+19x^2=-53+21 \\
\Leftrightarrow -8x^2 = -32 \\
\Leftrightarrow x^2 = \frac{-32}{-8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(4x^2+196=0 \\
\Leftrightarrow 4x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-11x^2-50=-8x^2-2 \\ \Leftrightarrow -11x^2+8x^2=-2+50 \\
\Leftrightarrow -3x^2 = 48 \\
\Leftrightarrow x^2 = \frac{48}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2-108=0 \\
\Leftrightarrow -3x^2 = 108 \\
\Leftrightarrow x^2 = \frac{108}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(-10x^2-2)=-(-36x^2+1344) \\ \Leftrightarrow 30x^2+6=36x^2-1344 \\
\Leftrightarrow 30x^2-36x^2=-1344-6 \\
\Leftrightarrow -6x^2 = -1350 \\
\Leftrightarrow x^2 = \frac{-1350}{-6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(7x^2+0=0 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(8x^2+329=10x^2-9 \\ \Leftrightarrow 8x^2-10x^2=-9-329 \\
\Leftrightarrow -2x^2 = -338 \\
\Leftrightarrow x^2 = \frac{-338}{-2}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)