Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-8x^2-153=-10x^2+9\)
- \(-3x^2+75=0\)
- \(-3(-4x^2-10)=-(-15x^2-177)\)
- \(-2(-3x^2-3)=-(-x^2-326)\)
- \(4(4x^2+5)=-(-17x^2+44)\)
- \(-10x^2-34=-2x^2-2\)
- \(4(7x^2+10)=-(-31x^2+107)\)
- \(3x^2+147=0\)
- \(6x^2-422=9x^2+10\)
- \(-4(10x^2+2)=-(46x^2-718)\)
- \(-8x^2-2=-3x^2-7\)
- \(8x^2-1152=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-8x^2-153=-10x^2+9 \\ \Leftrightarrow -8x^2+10x^2=9+153 \\
\Leftrightarrow 2x^2 = 162 \\
\Leftrightarrow x^2 = \frac{162}{2}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-3x^2+75=0 \\
\Leftrightarrow -3x^2 = -75 \\
\Leftrightarrow x^2 = \frac{-75}{-3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-3(-4x^2-10)=-(-15x^2-177) \\ \Leftrightarrow 12x^2+30=15x^2+177 \\
\Leftrightarrow 12x^2-15x^2=177-30 \\
\Leftrightarrow -3x^2 = 147 \\
\Leftrightarrow x^2 = \frac{147}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(-3x^2-3)=-(-x^2-326) \\ \Leftrightarrow 6x^2+6=x^2+326 \\
\Leftrightarrow 6x^2-x^2=326-6 \\
\Leftrightarrow 5x^2 = 320 \\
\Leftrightarrow x^2 = \frac{320}{5}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(4(4x^2+5)=-(-17x^2+44) \\ \Leftrightarrow 16x^2+20=17x^2-44 \\
\Leftrightarrow 16x^2-17x^2=-44-20 \\
\Leftrightarrow -x^2 = -64 \\
\Leftrightarrow x^2 = \frac{-64}{-1}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-10x^2-34=-2x^2-2 \\ \Leftrightarrow -10x^2+2x^2=-2+34 \\
\Leftrightarrow -8x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(7x^2+10)=-(-31x^2+107) \\ \Leftrightarrow 28x^2+40=31x^2-107 \\
\Leftrightarrow 28x^2-31x^2=-107-40 \\
\Leftrightarrow -3x^2 = -147 \\
\Leftrightarrow x^2 = \frac{-147}{-3}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(3x^2+147=0 \\
\Leftrightarrow 3x^2 = -147 \\
\Leftrightarrow x^2 = \frac{-147}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-422=9x^2+10 \\ \Leftrightarrow 6x^2-9x^2=10+422 \\
\Leftrightarrow -3x^2 = 432 \\
\Leftrightarrow x^2 = \frac{432}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(10x^2+2)=-(46x^2-718) \\ \Leftrightarrow -40x^2-8=-46x^2+718 \\
\Leftrightarrow -40x^2+46x^2=718+8 \\
\Leftrightarrow 6x^2 = 726 \\
\Leftrightarrow x^2 = \frac{726}{6}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-8x^2-2=-3x^2-7 \\ \Leftrightarrow -8x^2+3x^2=-7+2 \\
\Leftrightarrow -5x^2 = -5 \\
\Leftrightarrow x^2 = \frac{-5}{-5}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(8x^2-1152=0 \\
\Leftrightarrow 8x^2 = 1152 \\
\Leftrightarrow x^2 = \frac{1152}{8}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)