Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4(-3x^2-5)=-(-14x^2-182)\)
- \(5x^2+4=-2x^2+4\)
- \(x^2-96=-3x^2+4\)
- \(2(-5x^2-5)=-(8x^2-278)\)
- \(3x^2-125=2x^2-4\)
- \(-8x^2+200=0\)
- \(-14x^2+908=-10x^2+8\)
- \(8x^2-32=0\)
- \(-5(-2x^2-9)=-(-17x^2-45)\)
- \(-5(10x^2-9)=-(44x^2-339)\)
- \(8x^2+8=0\)
- \(-x^2+26=4x^2+6\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4(-3x^2-5)=-(-14x^2-182) \\ \Leftrightarrow 12x^2+20=14x^2+182 \\
\Leftrightarrow 12x^2-14x^2=182-20 \\
\Leftrightarrow -2x^2 = 162 \\
\Leftrightarrow x^2 = \frac{162}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+4=-2x^2+4 \\ \Leftrightarrow 5x^2+2x^2=4-4 \\
\Leftrightarrow 7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-96=-3x^2+4 \\ \Leftrightarrow x^2+3x^2=4+96 \\
\Leftrightarrow 4x^2 = 100 \\
\Leftrightarrow x^2 = \frac{100}{4}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(2(-5x^2-5)=-(8x^2-278) \\ \Leftrightarrow -10x^2-10=-8x^2+278 \\
\Leftrightarrow -10x^2+8x^2=278+10 \\
\Leftrightarrow -2x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2-125=2x^2-4 \\ \Leftrightarrow 3x^2-2x^2=-4+125 \\
\Leftrightarrow x^2 = 121 \\
\Leftrightarrow x^2 = \frac{121}{1}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-8x^2+200=0 \\
\Leftrightarrow -8x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{-8}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-14x^2+908=-10x^2+8 \\ \Leftrightarrow -14x^2+10x^2=8-908 \\
\Leftrightarrow -4x^2 = -900 \\
\Leftrightarrow x^2 = \frac{-900}{-4}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(8x^2-32=0 \\
\Leftrightarrow 8x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-5(-2x^2-9)=-(-17x^2-45) \\ \Leftrightarrow 10x^2+45=17x^2+45 \\
\Leftrightarrow 10x^2-17x^2=45-45 \\
\Leftrightarrow -7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(10x^2-9)=-(44x^2-339) \\ \Leftrightarrow -50x^2+45=-44x^2+339 \\
\Leftrightarrow -50x^2+44x^2=339-45 \\
\Leftrightarrow -6x^2 = 294 \\
\Leftrightarrow x^2 = \frac{294}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2+8=0 \\
\Leftrightarrow 8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2+26=4x^2+6 \\ \Leftrightarrow -x^2-4x^2=6-26 \\
\Leftrightarrow -5x^2 = -20 \\
\Leftrightarrow x^2 = \frac{-20}{-5}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)