Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(2(6x^2+8)=-(-5x^2-583)\)
- \(x^2+9=0\)
- \(6x^2-96=0\)
- \(3(4x^2+7)=-(-19x^2+154)\)
- \(6x^2-172=5x^2-3\)
- \(2(6x^2-10)=-(-10x^2+38)\)
- \(-5x^2+405=0\)
- \(2x^2+128=0\)
- \(4(7x^2+7)=-(-27x^2-37)\)
- \(7x^2-26=5x^2-8\)
- \(2x^2+50=0\)
- \(2(6x^2-3)=-(-17x^2-14)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(2(6x^2+8)=-(-5x^2-583) \\ \Leftrightarrow 12x^2+16=5x^2+583 \\
\Leftrightarrow 12x^2-5x^2=583-16 \\
\Leftrightarrow 7x^2 = 567 \\
\Leftrightarrow x^2 = \frac{567}{7}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(x^2+9=0 \\
\Leftrightarrow x^2 = -9 \\
\Leftrightarrow x^2 = \frac{-9}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-96=0 \\
\Leftrightarrow 6x^2 = 96 \\
\Leftrightarrow x^2 = \frac{96}{6}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(3(4x^2+7)=-(-19x^2+154) \\ \Leftrightarrow 12x^2+21=19x^2-154 \\
\Leftrightarrow 12x^2-19x^2=-154-21 \\
\Leftrightarrow -7x^2 = -175 \\
\Leftrightarrow x^2 = \frac{-175}{-7}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(6x^2-172=5x^2-3 \\ \Leftrightarrow 6x^2-5x^2=-3+172 \\
\Leftrightarrow x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(2(6x^2-10)=-(-10x^2+38) \\ \Leftrightarrow 12x^2-20=10x^2-38 \\
\Leftrightarrow 12x^2-10x^2=-38+20 \\
\Leftrightarrow 2x^2 = -18 \\
\Leftrightarrow x^2 = \frac{-18}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2+405=0 \\
\Leftrightarrow -5x^2 = -405 \\
\Leftrightarrow x^2 = \frac{-405}{-5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(2x^2+128=0 \\
\Leftrightarrow 2x^2 = -128 \\
\Leftrightarrow x^2 = \frac{-128}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(7x^2+7)=-(-27x^2-37) \\ \Leftrightarrow 28x^2+28=27x^2+37 \\
\Leftrightarrow 28x^2-27x^2=37-28 \\
\Leftrightarrow x^2 = 9 \\
\Leftrightarrow x^2 = \frac{9}{1}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(7x^2-26=5x^2-8 \\ \Leftrightarrow 7x^2-5x^2=-8+26 \\
\Leftrightarrow 2x^2 = 18 \\
\Leftrightarrow x^2 = \frac{18}{2}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(2x^2+50=0 \\
\Leftrightarrow 2x^2 = -50 \\
\Leftrightarrow x^2 = \frac{-50}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(6x^2-3)=-(-17x^2-14) \\ \Leftrightarrow 12x^2-6=17x^2+14 \\
\Leftrightarrow 12x^2-17x^2=14+6 \\
\Leftrightarrow -5x^2 = 20 \\
\Leftrightarrow x^2 = \frac{20}{-5} < 0 \\
V = \varnothing \\ -----------------\)