Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-6x^2-6=0\)
- \(-5x^2+474=-9x^2-10\)
- \(6x^2-1350=0\)
- \(5(4x^2-5)=-(-27x^2+1033)\)
- \(-4(-9x^2-8)=-(-43x^2+31)\)
- \(3x^2+0=0\)
- \(-5x^2+0=0\)
- \(2(-10x^2-9)=-(17x^2-282)\)
- \(-11x^2-92=-10x^2+8\)
- \(8x^2-41=6x^2-9\)
- \(4(9x^2-8)=-(-30x^2+86)\)
- \(2(-3x^2-5)=-(0x^2+1024)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-6x^2-6=0 \\
\Leftrightarrow -6x^2 = 6 \\
\Leftrightarrow x^2 = \frac{6}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2+474=-9x^2-10 \\ \Leftrightarrow -5x^2+9x^2=-10-474 \\
\Leftrightarrow 4x^2 = -484 \\
\Leftrightarrow x^2 = \frac{-484}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-1350=0 \\
\Leftrightarrow 6x^2 = 1350 \\
\Leftrightarrow x^2 = \frac{1350}{6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(5(4x^2-5)=-(-27x^2+1033) \\ \Leftrightarrow 20x^2-25=27x^2-1033 \\
\Leftrightarrow 20x^2-27x^2=-1033+25 \\
\Leftrightarrow -7x^2 = -1008 \\
\Leftrightarrow x^2 = \frac{-1008}{-7}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-4(-9x^2-8)=-(-43x^2+31) \\ \Leftrightarrow 36x^2+32=43x^2-31 \\
\Leftrightarrow 36x^2-43x^2=-31-32 \\
\Leftrightarrow -7x^2 = -63 \\
\Leftrightarrow x^2 = \frac{-63}{-7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(3x^2+0=0 \\
\Leftrightarrow 3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2+0=0 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(2(-10x^2-9)=-(17x^2-282) \\ \Leftrightarrow -20x^2-18=-17x^2+282 \\
\Leftrightarrow -20x^2+17x^2=282+18 \\
\Leftrightarrow -3x^2 = 300 \\
\Leftrightarrow x^2 = \frac{300}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-11x^2-92=-10x^2+8 \\ \Leftrightarrow -11x^2+10x^2=8+92 \\
\Leftrightarrow -x^2 = 100 \\
\Leftrightarrow x^2 = \frac{100}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2-41=6x^2-9 \\ \Leftrightarrow 8x^2-6x^2=-9+41 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(4(9x^2-8)=-(-30x^2+86) \\ \Leftrightarrow 36x^2-32=30x^2-86 \\
\Leftrightarrow 36x^2-30x^2=-86+32 \\
\Leftrightarrow 6x^2 = -54 \\
\Leftrightarrow x^2 = \frac{-54}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(-3x^2-5)=-(0x^2+1024) \\ \Leftrightarrow -6x^2-10=0x^2-1024 \\
\Leftrightarrow -6x^2+0x^2=-1024+10 \\
\Leftrightarrow -6x^2 = -1014 \\
\Leftrightarrow x^2 = \frac{-1014}{-6}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)