Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(6x^2-5)=-(-31x^2-24)\)
- \(-2(-2x^2-7)=-(-7x^2-377)\)
- \(-4(-2x^2-10)=-(-13x^2-45)\)
- \(10x^2-1158=2x^2-6\)
- \(-17x^2+1=-9x^2-7\)
- \(-2(8x^2+6)=-(17x^2-4)\)
- \(3(-9x^2+5)=-(34x^2-582)\)
- \(2x^2-242=0\)
- \(-2(5x^2-8)=-(3x^2+96)\)
- \(2x^2+64=-6x^2-8\)
- \(2x^2+377=8x^2-7\)
- \(8x^2-1568=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(6x^2-5)=-(-31x^2-24) \\ \Leftrightarrow 30x^2-25=31x^2+24 \\
\Leftrightarrow 30x^2-31x^2=24+25 \\
\Leftrightarrow -x^2 = 49 \\
\Leftrightarrow x^2 = \frac{49}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(-2x^2-7)=-(-7x^2-377) \\ \Leftrightarrow 4x^2+14=7x^2+377 \\
\Leftrightarrow 4x^2-7x^2=377-14 \\
\Leftrightarrow -3x^2 = 363 \\
\Leftrightarrow x^2 = \frac{363}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(-2x^2-10)=-(-13x^2-45) \\ \Leftrightarrow 8x^2+40=13x^2+45 \\
\Leftrightarrow 8x^2-13x^2=45-40 \\
\Leftrightarrow -5x^2 = 5 \\
\Leftrightarrow x^2 = \frac{5}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(10x^2-1158=2x^2-6 \\ \Leftrightarrow 10x^2-2x^2=-6+1158 \\
\Leftrightarrow 8x^2 = 1152 \\
\Leftrightarrow x^2 = \frac{1152}{8}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-17x^2+1=-9x^2-7 \\ \Leftrightarrow -17x^2+9x^2=-7-1 \\
\Leftrightarrow -8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-8}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-2(8x^2+6)=-(17x^2-4) \\ \Leftrightarrow -16x^2-12=-17x^2+4 \\
\Leftrightarrow -16x^2+17x^2=4+12 \\
\Leftrightarrow x^2 = 16 \\
\Leftrightarrow x^2 = \frac{16}{1}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(3(-9x^2+5)=-(34x^2-582) \\ \Leftrightarrow -27x^2+15=-34x^2+582 \\
\Leftrightarrow -27x^2+34x^2=582-15 \\
\Leftrightarrow 7x^2 = 567 \\
\Leftrightarrow x^2 = \frac{567}{7}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(2x^2-242=0 \\
\Leftrightarrow 2x^2 = 242 \\
\Leftrightarrow x^2 = \frac{242}{2}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-2(5x^2-8)=-(3x^2+96) \\ \Leftrightarrow -10x^2+16=-3x^2-96 \\
\Leftrightarrow -10x^2+3x^2=-96-16 \\
\Leftrightarrow -7x^2 = -112 \\
\Leftrightarrow x^2 = \frac{-112}{-7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(2x^2+64=-6x^2-8 \\ \Leftrightarrow 2x^2+6x^2=-8-64 \\
\Leftrightarrow 8x^2 = -72 \\
\Leftrightarrow x^2 = \frac{-72}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+377=8x^2-7 \\ \Leftrightarrow 2x^2-8x^2=-7-377 \\
\Leftrightarrow -6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{-6}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(8x^2-1568=0 \\
\Leftrightarrow 8x^2 = 1568 \\
\Leftrightarrow x^2 = \frac{1568}{8}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)