Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5x^2-245=0\)
- \(16x^2+720=10x^2-6\)
- \(-4x^2+4=0\)
- \(7x^2-503=4x^2+4\)
- \(-14x^2+279=-6x^2-9\)
- \(-6x^2+0=0\)
- \(-8x^2+128=0\)
- \(-x^2+1=0\)
- \(-2(8x^2+7)=-(13x^2+689)\)
- \(2(-10x^2-2)=-(18x^2+4)\)
- \(14x^2+5=10x^2+5\)
- \(x^2-100=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5x^2-245=0 \\
\Leftrightarrow 5x^2 = 245 \\
\Leftrightarrow x^2 = \frac{245}{5}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(16x^2+720=10x^2-6 \\ \Leftrightarrow 16x^2-10x^2=-6-720 \\
\Leftrightarrow 6x^2 = -726 \\
\Leftrightarrow x^2 = \frac{-726}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4x^2+4=0 \\
\Leftrightarrow -4x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{-4}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(7x^2-503=4x^2+4 \\ \Leftrightarrow 7x^2-4x^2=4+503 \\
\Leftrightarrow 3x^2 = 507 \\
\Leftrightarrow x^2 = \frac{507}{3}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-14x^2+279=-6x^2-9 \\ \Leftrightarrow -14x^2+6x^2=-9-279 \\
\Leftrightarrow -8x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{-8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-6x^2+0=0 \\
\Leftrightarrow -6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-8x^2+128=0 \\
\Leftrightarrow -8x^2 = -128 \\
\Leftrightarrow x^2 = \frac{-128}{-8}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-x^2+1=0 \\
\Leftrightarrow -x^2 = -1 \\
\Leftrightarrow x^2 = \frac{-1}{-1}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-2(8x^2+7)=-(13x^2+689) \\ \Leftrightarrow -16x^2-14=-13x^2-689 \\
\Leftrightarrow -16x^2+13x^2=-689+14 \\
\Leftrightarrow -3x^2 = -675 \\
\Leftrightarrow x^2 = \frac{-675}{-3}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(2(-10x^2-2)=-(18x^2+4) \\ \Leftrightarrow -20x^2-4=-18x^2-4 \\
\Leftrightarrow -20x^2+18x^2=-4+4 \\
\Leftrightarrow -2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(14x^2+5=10x^2+5 \\ \Leftrightarrow 14x^2-10x^2=5-5 \\
\Leftrightarrow 4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-100=0 \\
\Leftrightarrow x^2 = 100 \\
\Leftrightarrow x^2 = \frac{100}{1}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)