Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-6x^2+22x=0\)
- \(-2(2x^2+4x)=-(-3x^2-11x)\)
- \(2(-8x^2+8x)=-(15x^2+2x)\)
- \(-3(-9x^2+5x)=-(-30x^2+31x)\)
- \(-7x^2-16x=0\)
- \(x^2-10x=0\)
- \(4(7x^2-2x)=-(-26x^2-4x)\)
- \(-8x^2+5x=0\)
- \(-4(-2x^2+8x)=-(-16x^2+9x)\)
- \(-5x^2-21x=0\)
- \(-5x^2+7x=-2x^2-10x\)
- \(-4x^2-15x=-3x^2+8x\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-6x^2+22x=0 \\
\Leftrightarrow x(-6x+22) = 0 \\
\Leftrightarrow x = 0 \vee -6x+22=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-22}{-6} = \frac{11}{3} \\ V = \Big\{ \frac{11}{3}; 0 \Big\} \\ -----------------\)
- \(-2(2x^2+4x)=-(-3x^2-11x) \\ \Leftrightarrow -4x^2-8x=3x^2+11x \\
\Leftrightarrow -4x^2-8x-3x^2-11x= 0 \\
\Leftrightarrow -7x^2+19x=0 \\
\Leftrightarrow x(-7x+19) = 0 \\
\Leftrightarrow x = 0 \vee -7x+19=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-19}{-7} = \frac{19}{7} \\ V = \Big\{ \frac{19}{7}; 0 \Big\} \\ -----------------\)
- \(2(-8x^2+8x)=-(15x^2+2x) \\ \Leftrightarrow -16x^2+16x=-15x^2-2x \\
\Leftrightarrow -16x^2+16x+15x^2+2x= 0 \\
\Leftrightarrow -x^2-18x=0 \\
\Leftrightarrow x(-x-18) = 0 \\
\Leftrightarrow x = 0 \vee -x-18=0 \\
\Leftrightarrow x = 0 \vee x = \frac{18}{-1} = -18 \\ V = \Big\{ 0 ; -18 \Big\} \\ -----------------\)
- \(-3(-9x^2+5x)=-(-30x^2+31x) \\ \Leftrightarrow 27x^2-15x=30x^2-31x \\
\Leftrightarrow 27x^2-15x-30x^2+31x= 0 \\
\Leftrightarrow -3x^2-16x=0 \\
\Leftrightarrow x(-3x-16) = 0 \\
\Leftrightarrow x = 0 \vee -3x-16=0 \\
\Leftrightarrow x = 0 \vee x = \frac{16}{-3} = \frac{-16}{3} \\ V = \Big\{ 0 ; \frac{-16}{3} \Big\} \\ -----------------\)
- \(-7x^2-16x=0 \\
\Leftrightarrow x(-7x-16) = 0 \\
\Leftrightarrow x = 0 \vee -7x-16=0 \\
\Leftrightarrow x = 0 \vee x = \frac{16}{-7} = \frac{-16}{7} \\ V = \Big\{ 0 ; \frac{-16}{7} \Big\} \\ -----------------\)
- \(x^2-10x=0 \\
\Leftrightarrow x(x-10) = 0 \\
\Leftrightarrow x = 0 \vee x-10=0 \\
\Leftrightarrow x = 0 \vee x = \frac{10}{1} = 10 \\ V = \Big\{ 10; 0 \Big\} \\ -----------------\)
- \(4(7x^2-2x)=-(-26x^2-4x) \\ \Leftrightarrow 28x^2-8x=26x^2+4x \\
\Leftrightarrow 28x^2-8x-26x^2-4x= 0 \\
\Leftrightarrow 2x^2+12x=0 \\
\Leftrightarrow x(2x+12) = 0 \\
\Leftrightarrow x = 0 \vee 2x+12=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-12}{2} = -6 \\ V = \Big\{ 0 ; -6 \Big\} \\ -----------------\)
- \(-8x^2+5x=0 \\
\Leftrightarrow x(-8x+5) = 0 \\
\Leftrightarrow x = 0 \vee -8x+5=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-5}{-8} = \frac{5}{8} \\ V = \Big\{ \frac{5}{8}; 0 \Big\} \\ -----------------\)
- \(-4(-2x^2+8x)=-(-16x^2+9x) \\ \Leftrightarrow 8x^2-32x=16x^2-9x \\
\Leftrightarrow 8x^2-32x-16x^2+9x= 0 \\
\Leftrightarrow -8x^2+23x=0 \\
\Leftrightarrow x(-8x+23) = 0 \\
\Leftrightarrow x = 0 \vee -8x+23=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-23}{-8} = \frac{23}{8} \\ V = \Big\{ \frac{23}{8}; 0 \Big\} \\ -----------------\)
- \(-5x^2-21x=0 \\
\Leftrightarrow x(-5x-21) = 0 \\
\Leftrightarrow x = 0 \vee -5x-21=0 \\
\Leftrightarrow x = 0 \vee x = \frac{21}{-5} = \frac{-21}{5} \\ V = \Big\{ 0 ; \frac{-21}{5} \Big\} \\ -----------------\)
- \(-5x^2+7x=-2x^2-10x \\ \Leftrightarrow -3x^2+17x=0 \\
\Leftrightarrow x(-3x+17) = 0 \\
\Leftrightarrow x = 0 \vee -3x+17=0 \\
\Leftrightarrow x = 0 \vee x = \frac{-17}{-3} = \frac{17}{3} \\ V = \Big\{ \frac{17}{3}; 0 \Big\} \\ -----------------\)
- \(-4x^2-15x=-3x^2+8x \\ \Leftrightarrow -x^2-23x=0 \\
\Leftrightarrow x(-x-23) = 0 \\
\Leftrightarrow x = 0 \vee -x-23=0 \\
\Leftrightarrow x = 0 \vee x = \frac{23}{-1} = -23 \\ V = \Big\{ 0 ; -23 \Big\} \\ -----------------\)