Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(-10x^2+8)=-(-45x^2-940)\)
- \(-3x^2+108=0\)
- \(-7x^2+1183=0\)
- \(6x^2-40=10x^2-4\)
- \(-10x^2+6=-8x^2+6\)
- \(-2(-2x^2+7)=-(x^2+19)\)
- \(12x^2+672=9x^2-3\)
- \(7x^2+252=0\)
- \(-3x^2+5=5x^2+5\)
- \(3(-4x^2+2)=-(19x^2+1)\)
- \(-2(-10x^2+10)=-(-12x^2-12)\)
- \(6x^2+153=8x^2-9\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(-10x^2+8)=-(-45x^2-940) \\ \Leftrightarrow 50x^2-40=45x^2+940 \\
\Leftrightarrow 50x^2-45x^2=940+40 \\
\Leftrightarrow 5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{5}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-3x^2+108=0 \\
\Leftrightarrow -3x^2 = -108 \\
\Leftrightarrow x^2 = \frac{-108}{-3}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-7x^2+1183=0 \\
\Leftrightarrow -7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{-7}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(6x^2-40=10x^2-4 \\ \Leftrightarrow 6x^2-10x^2=-4+40 \\
\Leftrightarrow -4x^2 = 36 \\
\Leftrightarrow x^2 = \frac{36}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-10x^2+6=-8x^2+6 \\ \Leftrightarrow -10x^2+8x^2=6-6 \\
\Leftrightarrow -2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(-2x^2+7)=-(x^2+19) \\ \Leftrightarrow 4x^2-14=-x^2-19 \\
\Leftrightarrow 4x^2+x^2=-19+14 \\
\Leftrightarrow 5x^2 = -5 \\
\Leftrightarrow x^2 = \frac{-5}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(12x^2+672=9x^2-3 \\ \Leftrightarrow 12x^2-9x^2=-3-672 \\
\Leftrightarrow 3x^2 = -675 \\
\Leftrightarrow x^2 = \frac{-675}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2+252=0 \\
\Leftrightarrow 7x^2 = -252 \\
\Leftrightarrow x^2 = \frac{-252}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+5=5x^2+5 \\ \Leftrightarrow -3x^2-5x^2=5-5 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(3(-4x^2+2)=-(19x^2+1) \\ \Leftrightarrow -12x^2+6=-19x^2-1 \\
\Leftrightarrow -12x^2+19x^2=-1-6 \\
\Leftrightarrow 7x^2 = -7 \\
\Leftrightarrow x^2 = \frac{-7}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(-10x^2+10)=-(-12x^2-12) \\ \Leftrightarrow 20x^2-20=12x^2+12 \\
\Leftrightarrow 20x^2-12x^2=12+20 \\
\Leftrightarrow 8x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(6x^2+153=8x^2-9 \\ \Leftrightarrow 6x^2-8x^2=-9-153 \\
\Leftrightarrow -2x^2 = -162 \\
\Leftrightarrow x^2 = \frac{-162}{-2}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)