Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(17x^2-851=10x^2-4\)
- \(-x^2+7=-6x^2+7\)
- \(-8x^2-288=0\)
- \(-5x^2-845=0\)
- \(-3x^2+507=0\)
- \(-3(-9x^2+9)=-(-20x^2+1210)\)
- \(-3x^2+9=-5x^2-9\)
- \(-6x^2-33=-7x^2-8\)
- \(3x^2-675=0\)
- \(2x^2-338=0\)
- \(2x^2-72=0\)
- \(-2x^2-18=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(17x^2-851=10x^2-4 \\ \Leftrightarrow 17x^2-10x^2=-4+851 \\
\Leftrightarrow 7x^2 = 847 \\
\Leftrightarrow x^2 = \frac{847}{7}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-x^2+7=-6x^2+7 \\ \Leftrightarrow -x^2+6x^2=7-7 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-8x^2-288=0 \\
\Leftrightarrow -8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2-845=0 \\
\Leftrightarrow -5x^2 = 845 \\
\Leftrightarrow x^2 = \frac{845}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+507=0 \\
\Leftrightarrow -3x^2 = -507 \\
\Leftrightarrow x^2 = \frac{-507}{-3}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3(-9x^2+9)=-(-20x^2+1210) \\ \Leftrightarrow 27x^2-27=20x^2-1210 \\
\Leftrightarrow 27x^2-20x^2=-1210+27 \\
\Leftrightarrow 7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+9=-5x^2-9 \\ \Leftrightarrow -3x^2+5x^2=-9-9 \\
\Leftrightarrow 2x^2 = -18 \\
\Leftrightarrow x^2 = \frac{-18}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-6x^2-33=-7x^2-8 \\ \Leftrightarrow -6x^2+7x^2=-8+33 \\
\Leftrightarrow x^2 = 25 \\
\Leftrightarrow x^2 = \frac{25}{1}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(3x^2-675=0 \\
\Leftrightarrow 3x^2 = 675 \\
\Leftrightarrow x^2 = \frac{675}{3}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(2x^2-338=0 \\
\Leftrightarrow 2x^2 = 338 \\
\Leftrightarrow x^2 = \frac{338}{2}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(2x^2-72=0 \\
\Leftrightarrow 2x^2 = 72 \\
\Leftrightarrow x^2 = \frac{72}{2}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-2x^2-18=0 \\
\Leftrightarrow -2x^2 = 18 \\
\Leftrightarrow x^2 = \frac{18}{-2} < 0 \\
V = \varnothing \\ -----------------\)