Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-7x^2+1372=0\)
- \(x^2+64=0\)
- \(-3x^2-241=2x^2+4\)
- \(-7x^2+28=0\)
- \(4x^2-60=-3x^2+3\)
- \(-4(8x^2+8)=-(35x^2+29)\)
- \(8x^2-122=3x^2+3\)
- \(-4(-8x^2-4)=-(-38x^2-70)\)
- \(-11x^2+12=-6x^2-8\)
- \(2(-9x^2-4)=-(15x^2+440)\)
- \(-3x^2+50=3x^2-4\)
- \(-3x^2+260=4x^2+8\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-7x^2+1372=0 \\
\Leftrightarrow -7x^2 = -1372 \\
\Leftrightarrow x^2 = \frac{-1372}{-7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(x^2+64=0 \\
\Leftrightarrow x^2 = -64 \\
\Leftrightarrow x^2 = \frac{-64}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2-241=2x^2+4 \\ \Leftrightarrow -3x^2-2x^2=4+241 \\
\Leftrightarrow -5x^2 = 245 \\
\Leftrightarrow x^2 = \frac{245}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-7x^2+28=0 \\
\Leftrightarrow -7x^2 = -28 \\
\Leftrightarrow x^2 = \frac{-28}{-7}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(4x^2-60=-3x^2+3 \\ \Leftrightarrow 4x^2+3x^2=3+60 \\
\Leftrightarrow 7x^2 = 63 \\
\Leftrightarrow x^2 = \frac{63}{7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-4(8x^2+8)=-(35x^2+29) \\ \Leftrightarrow -32x^2-32=-35x^2-29 \\
\Leftrightarrow -32x^2+35x^2=-29+32 \\
\Leftrightarrow 3x^2 = 3 \\
\Leftrightarrow x^2 = \frac{3}{3}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(8x^2-122=3x^2+3 \\ \Leftrightarrow 8x^2-3x^2=3+122 \\
\Leftrightarrow 5x^2 = 125 \\
\Leftrightarrow x^2 = \frac{125}{5}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-4(-8x^2-4)=-(-38x^2-70) \\ \Leftrightarrow 32x^2+16=38x^2+70 \\
\Leftrightarrow 32x^2-38x^2=70-16 \\
\Leftrightarrow -6x^2 = 54 \\
\Leftrightarrow x^2 = \frac{54}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-11x^2+12=-6x^2-8 \\ \Leftrightarrow -11x^2+6x^2=-8-12 \\
\Leftrightarrow -5x^2 = -20 \\
\Leftrightarrow x^2 = \frac{-20}{-5}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(2(-9x^2-4)=-(15x^2+440) \\ \Leftrightarrow -18x^2-8=-15x^2-440 \\
\Leftrightarrow -18x^2+15x^2=-440+8 \\
\Leftrightarrow -3x^2 = -432 \\
\Leftrightarrow x^2 = \frac{-432}{-3}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-3x^2+50=3x^2-4 \\ \Leftrightarrow -3x^2-3x^2=-4-50 \\
\Leftrightarrow -6x^2 = -54 \\
\Leftrightarrow x^2 = \frac{-54}{-6}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-3x^2+260=4x^2+8 \\ \Leftrightarrow -3x^2-4x^2=8-260 \\
\Leftrightarrow -7x^2 = -252 \\
\Leftrightarrow x^2 = \frac{-252}{-7}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)