Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(-9x^2+10)=-(52x^2+797)\)
- \(2x^2+576=-5x^2+9\)
- \(8x^2-288=0\)
- \(3x^2+588=0\)
- \(-3(-8x^2-3)=-(-21x^2+498)\)
- \(-5(-3x^2+8)=-(-10x^2+60)\)
- \(5(2x^2+4)=-(-5x^2-1000)\)
- \(14x^2-2=9x^2+3\)
- \(-3(9x^2-10)=-(21x^2-324)\)
- \(x^2-221=-5x^2-5\)
- \(-2x^2+392=0\)
- \(x^2-169=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(-9x^2+10)=-(52x^2+797) \\ \Leftrightarrow -45x^2+50=-52x^2-797 \\
\Leftrightarrow -45x^2+52x^2=-797-50 \\
\Leftrightarrow 7x^2 = -847 \\
\Leftrightarrow x^2 = \frac{-847}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+576=-5x^2+9 \\ \Leftrightarrow 2x^2+5x^2=9-576 \\
\Leftrightarrow 7x^2 = -567 \\
\Leftrightarrow x^2 = \frac{-567}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2-288=0 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(3x^2+588=0 \\
\Leftrightarrow 3x^2 = -588 \\
\Leftrightarrow x^2 = \frac{-588}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(-8x^2-3)=-(-21x^2+498) \\ \Leftrightarrow 24x^2+9=21x^2-498 \\
\Leftrightarrow 24x^2-21x^2=-498-9 \\
\Leftrightarrow 3x^2 = -507 \\
\Leftrightarrow x^2 = \frac{-507}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(-3x^2+8)=-(-10x^2+60) \\ \Leftrightarrow 15x^2-40=10x^2-60 \\
\Leftrightarrow 15x^2-10x^2=-60+40 \\
\Leftrightarrow 5x^2 = -20 \\
\Leftrightarrow x^2 = \frac{-20}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(5(2x^2+4)=-(-5x^2-1000) \\ \Leftrightarrow 10x^2+20=5x^2+1000 \\
\Leftrightarrow 10x^2-5x^2=1000-20 \\
\Leftrightarrow 5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{5}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(14x^2-2=9x^2+3 \\ \Leftrightarrow 14x^2-9x^2=3+2 \\
\Leftrightarrow 5x^2 = 5 \\
\Leftrightarrow x^2 = \frac{5}{5}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-3(9x^2-10)=-(21x^2-324) \\ \Leftrightarrow -27x^2+30=-21x^2+324 \\
\Leftrightarrow -27x^2+21x^2=324-30 \\
\Leftrightarrow -6x^2 = 294 \\
\Leftrightarrow x^2 = \frac{294}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2-221=-5x^2-5 \\ \Leftrightarrow x^2+5x^2=-5+221 \\
\Leftrightarrow 6x^2 = 216 \\
\Leftrightarrow x^2 = \frac{216}{6}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-2x^2+392=0 \\
\Leftrightarrow -2x^2 = -392 \\
\Leftrightarrow x^2 = \frac{-392}{-2}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(x^2-169=0 \\
\Leftrightarrow x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)