Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(-9x^2+2x)=-(23x^2-12x)\)
- \(2x^2-7x=7x^2+6x\)
- \(6x^2+23x=0\)
- \(-2(2x^2-8x)=-(5x^2-32x)\)
- \(3x^2+10x=0\)
- \(-7x^2+19x=0\)
- \(-5x^2-x=2x^2-5x\)
- \(4x^2-27x=-3x^2-7x\)
- \(-5x^2+15x=0\)
- \(-7x^2+18x=0\)
- \(-12x^2-22x=-4x^2-7x\)
- \(-x^2+4x=-3x^2-3x\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(-9x^2+2x)=-(23x^2-12x) \\ \Leftrightarrow -18x^2+4x=-23x^2+12x \\
\Leftrightarrow -18x^2+4x+23x^2-12x= 0 \\
\Leftrightarrow 5x^2+8x=0 \\
\Leftrightarrow x(5x+8) = 0 \\
\Leftrightarrow x = 0 \vee 5x+8=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-8}{5} \\ V = \Big\{ 0 ; \frac{-8}{5} \Big\} \\ -----------------\)
- \(2x^2-7x=7x^2+6x \\ \Leftrightarrow -5x^2-13x=0 \\
\Leftrightarrow x(-5x-13) = 0 \\
\Leftrightarrow x = 0 \vee -5x-13=0 \\
\Leftrightarrow x = 0 \vee x = \frac{13}{-5} = \frac{-13}{5} \\ V = \Big\{ 0 ; \frac{-13}{5} \Big\} \\ -----------------\)
- \(6x^2+23x=0 \\
\Leftrightarrow x(6x+23) = 0 \\
\Leftrightarrow x = 0 \vee 6x+23=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-23}{6} \\ V = \Big\{ 0 ; \frac{-23}{6} \Big\} \\ -----------------\)
- \(-2(2x^2-8x)=-(5x^2-32x) \\ \Leftrightarrow -4x^2+16x=-5x^2+32x \\
\Leftrightarrow -4x^2+16x+5x^2-32x= 0 \\
\Leftrightarrow x^2+16x=0 \\
\Leftrightarrow x(x+16) = 0 \\
\Leftrightarrow x = 0 \vee x+16=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-16}{1} = -16 \\ V = \Big\{ 0 ; -16 \Big\} \\ -----------------\)
- \(3x^2+10x=0 \\
\Leftrightarrow x(3x+10) = 0 \\
\Leftrightarrow x = 0 \vee 3x+10=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-10}{3} \\ V = \Big\{ 0 ; \frac{-10}{3} \Big\} \\ -----------------\)
- \(-7x^2+19x=0 \\
\Leftrightarrow x(-7x+19) = 0 \\
\Leftrightarrow x = 0 \vee -7x+19=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-19}{-7} = \frac{19}{7} \\ V = \Big\{ \frac{19}{7}; 0 \Big\} \\ -----------------\)
- \(-5x^2-x=2x^2-5x \\ \Leftrightarrow -7x^2+4x=0 \\
\Leftrightarrow x(-7x+4) = 0 \\
\Leftrightarrow x = 0 \vee -7x+4=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-4}{-7} = \frac{4}{7} \\ V = \Big\{ \frac{4}{7}; 0 \Big\} \\ -----------------\)
- \(4x^2-27x=-3x^2-7x \\ \Leftrightarrow 7x^2-20x=0 \\
\Leftrightarrow x(7x-20) = 0 \\
\Leftrightarrow x = 0 \vee 7x-20=0 \\
\Leftrightarrow x = 0 \vee x = \frac{20}{7} \\ V = \Big\{ \frac{20}{7}; 0 \Big\} \\ -----------------\)
- \(-5x^2+15x=0 \\
\Leftrightarrow x(-5x+15) = 0 \\
\Leftrightarrow x = 0 \vee -5x+15=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-15}{-5} = 3 \\ V = \Big\{ 3; 0 \Big\} \\ -----------------\)
- \(-7x^2+18x=0 \\
\Leftrightarrow x(-7x+18) = 0 \\
\Leftrightarrow x = 0 \vee -7x+18=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-18}{-7} = \frac{18}{7} \\ V = \Big\{ \frac{18}{7}; 0 \Big\} \\ -----------------\)
- \(-12x^2-22x=-4x^2-7x \\ \Leftrightarrow -8x^2-15x=0 \\
\Leftrightarrow x(-8x-15) = 0 \\
\Leftrightarrow x = 0 \vee -8x-15=0 \\
\Leftrightarrow x = 0 \vee x = \frac{15}{-8} = \frac{-15}{8} \\ V = \Big\{ 0 ; \frac{-15}{8} \Big\} \\ -----------------\)
- \(-x^2+4x=-3x^2-3x \\ \Leftrightarrow 2x^2+7x=0 \\
\Leftrightarrow x(2x+7) = 0 \\
\Leftrightarrow x = 0 \vee 2x+7=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-7}{2} \\ V = \Big\{ 0 ; \frac{-7}{2} \Big\} \\ -----------------\)