Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(-6x^2-4)=-(33x^2+8)\)
- \(-x^2-26=-3x^2+6\)
- \(2x^2+98=0\)
- \(-x^2-1810=-9x^2-10\)
- \(3(-8x^2-9)=-(30x^2-1149)\)
- \(5(-3x^2-10)=-(16x^2-146)\)
- \(-3x^2+75=0\)
- \(-5(-2x^2-6)=-(-4x^2-6)\)
- \(-3(-5x^2-10)=-(-9x^2-246)\)
- \(13x^2-34=5x^2-2\)
- \(16x^2-5=10x^2-5\)
- \(5x^2+980=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(-6x^2-4)=-(33x^2+8) \\ \Leftrightarrow -30x^2-20=-33x^2-8 \\
\Leftrightarrow -30x^2+33x^2=-8+20 \\
\Leftrightarrow 3x^2 = 12 \\
\Leftrightarrow x^2 = \frac{12}{3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-x^2-26=-3x^2+6 \\ \Leftrightarrow -x^2+3x^2=6+26 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(2x^2+98=0 \\
\Leftrightarrow 2x^2 = -98 \\
\Leftrightarrow x^2 = \frac{-98}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2-1810=-9x^2-10 \\ \Leftrightarrow -x^2+9x^2=-10+1810 \\
\Leftrightarrow 8x^2 = 1800 \\
\Leftrightarrow x^2 = \frac{1800}{8}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(3(-8x^2-9)=-(30x^2-1149) \\ \Leftrightarrow -24x^2-27=-30x^2+1149 \\
\Leftrightarrow -24x^2+30x^2=1149+27 \\
\Leftrightarrow 6x^2 = 1176 \\
\Leftrightarrow x^2 = \frac{1176}{6}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(5(-3x^2-10)=-(16x^2-146) \\ \Leftrightarrow -15x^2-50=-16x^2+146 \\
\Leftrightarrow -15x^2+16x^2=146+50 \\
\Leftrightarrow x^2 = 196 \\
\Leftrightarrow x^2 = \frac{196}{1}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-3x^2+75=0 \\
\Leftrightarrow -3x^2 = -75 \\
\Leftrightarrow x^2 = \frac{-75}{-3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-5(-2x^2-6)=-(-4x^2-6) \\ \Leftrightarrow 10x^2+30=4x^2+6 \\
\Leftrightarrow 10x^2-4x^2=6-30 \\
\Leftrightarrow 6x^2 = -24 \\
\Leftrightarrow x^2 = \frac{-24}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(-5x^2-10)=-(-9x^2-246) \\ \Leftrightarrow 15x^2+30=9x^2+246 \\
\Leftrightarrow 15x^2-9x^2=246-30 \\
\Leftrightarrow 6x^2 = 216 \\
\Leftrightarrow x^2 = \frac{216}{6}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(13x^2-34=5x^2-2 \\ \Leftrightarrow 13x^2-5x^2=-2+34 \\
\Leftrightarrow 8x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(16x^2-5=10x^2-5 \\ \Leftrightarrow 16x^2-10x^2=-5+5 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2+980=0 \\
\Leftrightarrow 5x^2 = -980 \\
\Leftrightarrow x^2 = \frac{-980}{5} < 0 \\
V = \varnothing \\ -----------------\)