Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-13x^2+38=-5x^2+6\)
- \(-5x^2+241=-2x^2-2\)
- \(7x^2+448=0\)
- \(-2x^2-186=-5x^2+6\)
- \(-5(-10x^2+3)=-(-56x^2+69)\)
- \(4(-7x^2+4)=-(31x^2-163)\)
- \(-2(-2x^2+3)=-(-8x^2+22)\)
- \(6x^2+726=0\)
- \(x^2-582=4x^2+6\)
- \(-3x^2+507=0\)
- \(-3(10x^2+6)=-(23x^2-549)\)
- \(-14x^2+686=-10x^2+10\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-13x^2+38=-5x^2+6 \\ \Leftrightarrow -13x^2+5x^2=6-38 \\
\Leftrightarrow -8x^2 = -32 \\
\Leftrightarrow x^2 = \frac{-32}{-8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-5x^2+241=-2x^2-2 \\ \Leftrightarrow -5x^2+2x^2=-2-241 \\
\Leftrightarrow -3x^2 = -243 \\
\Leftrightarrow x^2 = \frac{-243}{-3}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(7x^2+448=0 \\
\Leftrightarrow 7x^2 = -448 \\
\Leftrightarrow x^2 = \frac{-448}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2-186=-5x^2+6 \\ \Leftrightarrow -2x^2+5x^2=6+186 \\
\Leftrightarrow 3x^2 = 192 \\
\Leftrightarrow x^2 = \frac{192}{3}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-5(-10x^2+3)=-(-56x^2+69) \\ \Leftrightarrow 50x^2-15=56x^2-69 \\
\Leftrightarrow 50x^2-56x^2=-69+15 \\
\Leftrightarrow -6x^2 = -54 \\
\Leftrightarrow x^2 = \frac{-54}{-6}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(4(-7x^2+4)=-(31x^2-163) \\ \Leftrightarrow -28x^2+16=-31x^2+163 \\
\Leftrightarrow -28x^2+31x^2=163-16 \\
\Leftrightarrow 3x^2 = 147 \\
\Leftrightarrow x^2 = \frac{147}{3}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-2(-2x^2+3)=-(-8x^2+22) \\ \Leftrightarrow 4x^2-6=8x^2-22 \\
\Leftrightarrow 4x^2-8x^2=-22+6 \\
\Leftrightarrow -4x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{-4}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(6x^2+726=0 \\
\Leftrightarrow 6x^2 = -726 \\
\Leftrightarrow x^2 = \frac{-726}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2-582=4x^2+6 \\ \Leftrightarrow x^2-4x^2=6+582 \\
\Leftrightarrow -3x^2 = 588 \\
\Leftrightarrow x^2 = \frac{588}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+507=0 \\
\Leftrightarrow -3x^2 = -507 \\
\Leftrightarrow x^2 = \frac{-507}{-3}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3(10x^2+6)=-(23x^2-549) \\ \Leftrightarrow -30x^2-18=-23x^2+549 \\
\Leftrightarrow -30x^2+23x^2=549+18 \\
\Leftrightarrow -7x^2 = 567 \\
\Leftrightarrow x^2 = \frac{567}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-14x^2+686=-10x^2+10 \\ \Leftrightarrow -14x^2+10x^2=10-686 \\
\Leftrightarrow -4x^2 = -676 \\
\Leftrightarrow x^2 = \frac{-676}{-4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)