Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-x^2-795=-9x^2+5\)
- \(5(-7x^2-5)=-(38x^2-23)\)
- \(5(8x^2-10)=-(-42x^2+50)\)
- \(-4x^2+0=0\)
- \(-8x^2+0=0\)
- \(-x^2-13=-4x^2-10\)
- \(-12x^2+102=-10x^2+4\)
- \(4x^2-144=0\)
- \(-2(-3x^2-7)=-(-12x^2+82)\)
- \(8x^2+0=0\)
- \(3x^2-12=0\)
- \(-3(2x^2-9)=-(2x^2+169)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-x^2-795=-9x^2+5 \\ \Leftrightarrow -x^2+9x^2=5+795 \\
\Leftrightarrow 8x^2 = 800 \\
\Leftrightarrow x^2 = \frac{800}{8}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(5(-7x^2-5)=-(38x^2-23) \\ \Leftrightarrow -35x^2-25=-38x^2+23 \\
\Leftrightarrow -35x^2+38x^2=23+25 \\
\Leftrightarrow 3x^2 = 48 \\
\Leftrightarrow x^2 = \frac{48}{3}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(5(8x^2-10)=-(-42x^2+50) \\ \Leftrightarrow 40x^2-50=42x^2-50 \\
\Leftrightarrow 40x^2-42x^2=-50+50 \\
\Leftrightarrow -2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-4x^2+0=0 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-8x^2+0=0 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-x^2-13=-4x^2-10 \\ \Leftrightarrow -x^2+4x^2=-10+13 \\
\Leftrightarrow 3x^2 = 3 \\
\Leftrightarrow x^2 = \frac{3}{3}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-12x^2+102=-10x^2+4 \\ \Leftrightarrow -12x^2+10x^2=4-102 \\
\Leftrightarrow -2x^2 = -98 \\
\Leftrightarrow x^2 = \frac{-98}{-2}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(4x^2-144=0 \\
\Leftrightarrow 4x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{4}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-2(-3x^2-7)=-(-12x^2+82) \\ \Leftrightarrow 6x^2+14=12x^2-82 \\
\Leftrightarrow 6x^2-12x^2=-82-14 \\
\Leftrightarrow -6x^2 = -96 \\
\Leftrightarrow x^2 = \frac{-96}{-6}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(8x^2+0=0 \\
\Leftrightarrow 8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(3x^2-12=0 \\
\Leftrightarrow 3x^2 = 12 \\
\Leftrightarrow x^2 = \frac{12}{3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-3(2x^2-9)=-(2x^2+169) \\ \Leftrightarrow -6x^2+27=-2x^2-169 \\
\Leftrightarrow -6x^2+2x^2=-169-27 \\
\Leftrightarrow -4x^2 = -196 \\
\Leftrightarrow x^2 = \frac{-196}{-4}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)