Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-x^2-225=0\)
- \(2x^2+242=0\)
- \(4(6x^2-5)=-(-26x^2-318)\)
- \(14x^2-1348=8x^2+2\)
- \(-10x^2-679=-7x^2-4\)
- \(3(-7x^2-7)=-(17x^2+805)\)
- \(3(-2x^2-9)=-(9x^2+27)\)
- \(-17x^2+1577=-9x^2+9\)
- \(6x^2-2=4x^2-2\)
- \(x^2-1157=-7x^2-5\)
- \(-8x^2-968=0\)
- \(-7x^2+157=-4x^2+10\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-x^2-225=0 \\
\Leftrightarrow -x^2 = 225 \\
\Leftrightarrow x^2 = \frac{225}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+242=0 \\
\Leftrightarrow 2x^2 = -242 \\
\Leftrightarrow x^2 = \frac{-242}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(6x^2-5)=-(-26x^2-318) \\ \Leftrightarrow 24x^2-20=26x^2+318 \\
\Leftrightarrow 24x^2-26x^2=318+20 \\
\Leftrightarrow -2x^2 = 338 \\
\Leftrightarrow x^2 = \frac{338}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(14x^2-1348=8x^2+2 \\ \Leftrightarrow 14x^2-8x^2=2+1348 \\
\Leftrightarrow 6x^2 = 1350 \\
\Leftrightarrow x^2 = \frac{1350}{6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-10x^2-679=-7x^2-4 \\ \Leftrightarrow -10x^2+7x^2=-4+679 \\
\Leftrightarrow -3x^2 = 675 \\
\Leftrightarrow x^2 = \frac{675}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(-7x^2-7)=-(17x^2+805) \\ \Leftrightarrow -21x^2-21=-17x^2-805 \\
\Leftrightarrow -21x^2+17x^2=-805+21 \\
\Leftrightarrow -4x^2 = -784 \\
\Leftrightarrow x^2 = \frac{-784}{-4}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(3(-2x^2-9)=-(9x^2+27) \\ \Leftrightarrow -6x^2-27=-9x^2-27 \\
\Leftrightarrow -6x^2+9x^2=-27+27 \\
\Leftrightarrow 3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-17x^2+1577=-9x^2+9 \\ \Leftrightarrow -17x^2+9x^2=9-1577 \\
\Leftrightarrow -8x^2 = -1568 \\
\Leftrightarrow x^2 = \frac{-1568}{-8}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(6x^2-2=4x^2-2 \\ \Leftrightarrow 6x^2-4x^2=-2+2 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-1157=-7x^2-5 \\ \Leftrightarrow x^2+7x^2=-5+1157 \\
\Leftrightarrow 8x^2 = 1152 \\
\Leftrightarrow x^2 = \frac{1152}{8}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-8x^2-968=0 \\
\Leftrightarrow -8x^2 = 968 \\
\Leftrightarrow x^2 = \frac{968}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-7x^2+157=-4x^2+10 \\ \Leftrightarrow -7x^2+4x^2=10-157 \\
\Leftrightarrow -3x^2 = -147 \\
\Leftrightarrow x^2 = \frac{-147}{-3}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)