Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-6x^2+7=2x^2+7\)
- \(2x^2-50=0\)
- \(4(10x^2-2)=-(-41x^2+204)\)
- \(-9x^2-777=-5x^2+7\)
- \(5x^2+125=0\)
- \(9x^2-98=6x^2+10\)
- \(-4x^2+256=0\)
- \(-3x^2-371=-6x^2-8\)
- \(2x^2-285=-4x^2+9\)
- \(-8x^2+72=0\)
- \(18x^2-10=10x^2-10\)
- \(x^2+70=8x^2+7\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-6x^2+7=2x^2+7 \\ \Leftrightarrow -6x^2-2x^2=7-7 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(2x^2-50=0 \\
\Leftrightarrow 2x^2 = 50 \\
\Leftrightarrow x^2 = \frac{50}{2}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(4(10x^2-2)=-(-41x^2+204) \\ \Leftrightarrow 40x^2-8=41x^2-204 \\
\Leftrightarrow 40x^2-41x^2=-204+8 \\
\Leftrightarrow -x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{-1}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-9x^2-777=-5x^2+7 \\ \Leftrightarrow -9x^2+5x^2=7+777 \\
\Leftrightarrow -4x^2 = 784 \\
\Leftrightarrow x^2 = \frac{784}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+125=0 \\
\Leftrightarrow 5x^2 = -125 \\
\Leftrightarrow x^2 = \frac{-125}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(9x^2-98=6x^2+10 \\ \Leftrightarrow 9x^2-6x^2=10+98 \\
\Leftrightarrow 3x^2 = 108 \\
\Leftrightarrow x^2 = \frac{108}{3}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-4x^2+256=0 \\
\Leftrightarrow -4x^2 = -256 \\
\Leftrightarrow x^2 = \frac{-256}{-4}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-3x^2-371=-6x^2-8 \\ \Leftrightarrow -3x^2+6x^2=-8+371 \\
\Leftrightarrow 3x^2 = 363 \\
\Leftrightarrow x^2 = \frac{363}{3}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(2x^2-285=-4x^2+9 \\ \Leftrightarrow 2x^2+4x^2=9+285 \\
\Leftrightarrow 6x^2 = 294 \\
\Leftrightarrow x^2 = \frac{294}{6}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-8x^2+72=0 \\
\Leftrightarrow -8x^2 = -72 \\
\Leftrightarrow x^2 = \frac{-72}{-8}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(18x^2-10=10x^2-10 \\ \Leftrightarrow 18x^2-10x^2=-10+10 \\
\Leftrightarrow 8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2+70=8x^2+7 \\ \Leftrightarrow x^2-8x^2=7-70 \\
\Leftrightarrow -7x^2 = -63 \\
\Leftrightarrow x^2 = \frac{-63}{-7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)