Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-3(-6x^2-2x)=-(-22x^2-22x)\)
- \(-x^2+14x=0\)
- \(x^2+18x=-3x^2-7x\)
- \(-8x^2-9x=-9x^2+4x\)
- \(-5(-3x^2+5x)=-(-22x^2+3x)\)
- \(8x^2+5x=0\)
- \(-8x^2+18x=-10x^2+10x\)
- \(4x^2+19x=0\)
- \(-3x^2-11x=0\)
- \(3x^2+16x=-5x^2-4x\)
- \(x^2-18x=0\)
- \(-8x^2+25x=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-3(-6x^2-2x)=-(-22x^2-22x) \\ \Leftrightarrow 18x^2+6x=22x^2+22x \\
\Leftrightarrow 18x^2+6x-22x^2-22x= 0 \\
\Leftrightarrow -4x^2+16x=0 \\
\Leftrightarrow x(-4x+16) = 0 \\
\Leftrightarrow x = 0 \vee -4x+16=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-16}{-4} = 4 \\ V = \Big\{ 4; 0 \Big\} \\ -----------------\)
- \(-x^2+14x=0 \\
\Leftrightarrow x(-x+14) = 0 \\
\Leftrightarrow x = 0 \vee -x+14=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-14}{-1} = 14 \\ V = \Big\{ 14; 0 \Big\} \\ -----------------\)
- \(x^2+18x=-3x^2-7x \\ \Leftrightarrow 4x^2+25x=0 \\
\Leftrightarrow x(4x+25) = 0 \\
\Leftrightarrow x = 0 \vee 4x+25=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-25}{4} \\ V = \Big\{ 0 ; \frac{-25}{4} \Big\} \\ -----------------\)
- \(-8x^2-9x=-9x^2+4x \\ \Leftrightarrow x^2-13x=0 \\
\Leftrightarrow x(x-13) = 0 \\
\Leftrightarrow x = 0 \vee x-13=0 \\
\Leftrightarrow x = 0 \vee x = \frac{13}{1} = 13 \\ V = \Big\{ 13; 0 \Big\} \\ -----------------\)
- \(-5(-3x^2+5x)=-(-22x^2+3x) \\ \Leftrightarrow 15x^2-25x=22x^2-3x \\
\Leftrightarrow 15x^2-25x-22x^2+3x= 0 \\
\Leftrightarrow -7x^2+22x=0 \\
\Leftrightarrow x(-7x+22) = 0 \\
\Leftrightarrow x = 0 \vee -7x+22=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-22}{-7} = \frac{22}{7} \\ V = \Big\{ \frac{22}{7}; 0 \Big\} \\ -----------------\)
- \(8x^2+5x=0 \\
\Leftrightarrow x(8x+5) = 0 \\
\Leftrightarrow x = 0 \vee 8x+5=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-5}{8} \\ V = \Big\{ 0 ; \frac{-5}{8} \Big\} \\ -----------------\)
- \(-8x^2+18x=-10x^2+10x \\ \Leftrightarrow 2x^2+8x=0 \\
\Leftrightarrow x(2x+8) = 0 \\
\Leftrightarrow x = 0 \vee 2x+8=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-8}{2} = -4 \\ V = \Big\{ 0 ; -4 \Big\} \\ -----------------\)
- \(4x^2+19x=0 \\
\Leftrightarrow x(4x+19) = 0 \\
\Leftrightarrow x = 0 \vee 4x+19=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-19}{4} \\ V = \Big\{ 0 ; \frac{-19}{4} \Big\} \\ -----------------\)
- \(-3x^2-11x=0 \\
\Leftrightarrow x(-3x-11) = 0 \\
\Leftrightarrow x = 0 \vee -3x-11=0 \\
\Leftrightarrow x = 0 \vee x = \frac{11}{-3} = \frac{-11}{3} \\ V = \Big\{ 0 ; \frac{-11}{3} \Big\} \\ -----------------\)
- \(3x^2+16x=-5x^2-4x \\ \Leftrightarrow 8x^2+20x=0 \\
\Leftrightarrow x(8x+20) = 0 \\
\Leftrightarrow x = 0 \vee 8x+20=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-20}{8} = \frac{-5}{2} \\ V = \Big\{ 0 ; \frac{-5}{2} \Big\} \\ -----------------\)
- \(x^2-18x=0 \\
\Leftrightarrow x(x-18) = 0 \\
\Leftrightarrow x = 0 \vee x-18=0 \\
\Leftrightarrow x = 0 \vee x = \frac{18}{1} = 18 \\ V = \Big\{ 18; 0 \Big\} \\ -----------------\)
- \(-8x^2+25x=0 \\
\Leftrightarrow x(-8x+25) = 0 \\
\Leftrightarrow x = 0 \vee -8x+25=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-25}{-8} = \frac{25}{8} \\ V = \Big\{ \frac{25}{8}; 0 \Big\} \\ -----------------\)