Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(4(4x^2+4)=-(-10x^2-742)\)
- \(-3(5x^2+8)=-(18x^2+51)\)
- \(x^2-16=0\)
- \(5x^2+80=0\)
- \(-3(4x^2-4)=-(11x^2-12)\)
- \(x^2-81=0\)
- \(10x^2-1567=3x^2+8\)
- \(-3x^2-75=0\)
- \(-4(6x^2-3)=-(29x^2-12)\)
- \(x^2-1119=6x^2+6\)
- \(15x^2-298=7x^2-10\)
- \(3x^2+6=6x^2+6\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(4(4x^2+4)=-(-10x^2-742) \\ \Leftrightarrow 16x^2+16=10x^2+742 \\
\Leftrightarrow 16x^2-10x^2=742-16 \\
\Leftrightarrow 6x^2 = 726 \\
\Leftrightarrow x^2 = \frac{726}{6}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-3(5x^2+8)=-(18x^2+51) \\ \Leftrightarrow -15x^2-24=-18x^2-51 \\
\Leftrightarrow -15x^2+18x^2=-51+24 \\
\Leftrightarrow 3x^2 = -27 \\
\Leftrightarrow x^2 = \frac{-27}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2-16=0 \\
\Leftrightarrow x^2 = 16 \\
\Leftrightarrow x^2 = \frac{16}{1}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(5x^2+80=0 \\
\Leftrightarrow 5x^2 = -80 \\
\Leftrightarrow x^2 = \frac{-80}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(4x^2-4)=-(11x^2-12) \\ \Leftrightarrow -12x^2+12=-11x^2+12 \\
\Leftrightarrow -12x^2+11x^2=12-12 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-81=0 \\
\Leftrightarrow x^2 = 81 \\
\Leftrightarrow x^2 = \frac{81}{1}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(10x^2-1567=3x^2+8 \\ \Leftrightarrow 10x^2-3x^2=8+1567 \\
\Leftrightarrow 7x^2 = 1575 \\
\Leftrightarrow x^2 = \frac{1575}{7}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-3x^2-75=0 \\
\Leftrightarrow -3x^2 = 75 \\
\Leftrightarrow x^2 = \frac{75}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(6x^2-3)=-(29x^2-12) \\ \Leftrightarrow -24x^2+12=-29x^2+12 \\
\Leftrightarrow -24x^2+29x^2=12-12 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(x^2-1119=6x^2+6 \\ \Leftrightarrow x^2-6x^2=6+1119 \\
\Leftrightarrow -5x^2 = 1125 \\
\Leftrightarrow x^2 = \frac{1125}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(15x^2-298=7x^2-10 \\ \Leftrightarrow 15x^2-7x^2=-10+298 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(3x^2+6=6x^2+6 \\ \Leftrightarrow 3x^2-6x^2=6-6 \\
\Leftrightarrow -3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)