Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(x^2+66=9x^2-6\)
- \(7x^2-1372=0\)
- \(-2(-5x^2-5)=-(-6x^2-686)\)
- \(-x^2+0=0\)
- \(8x^2-1152=0\)
- \(14x^2-43=9x^2+2\)
- \(-3x^2-101=-6x^2+7\)
- \(3x^2-1581=-4x^2-6\)
- \(6x^2+0=0\)
- \(-5(-3x^2+3)=-(-8x^2+862)\)
- \(2x^2+200=0\)
- \(4(-9x^2-10)=-(34x^2+48)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(x^2+66=9x^2-6 \\ \Leftrightarrow x^2-9x^2=-6-66 \\
\Leftrightarrow -8x^2 = -72 \\
\Leftrightarrow x^2 = \frac{-72}{-8}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(7x^2-1372=0 \\
\Leftrightarrow 7x^2 = 1372 \\
\Leftrightarrow x^2 = \frac{1372}{7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-2(-5x^2-5)=-(-6x^2-686) \\ \Leftrightarrow 10x^2+10=6x^2+686 \\
\Leftrightarrow 10x^2-6x^2=686-10 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-x^2+0=0 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(8x^2-1152=0 \\
\Leftrightarrow 8x^2 = 1152 \\
\Leftrightarrow x^2 = \frac{1152}{8}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(14x^2-43=9x^2+2 \\ \Leftrightarrow 14x^2-9x^2=2+43 \\
\Leftrightarrow 5x^2 = 45 \\
\Leftrightarrow x^2 = \frac{45}{5}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-3x^2-101=-6x^2+7 \\ \Leftrightarrow -3x^2+6x^2=7+101 \\
\Leftrightarrow 3x^2 = 108 \\
\Leftrightarrow x^2 = \frac{108}{3}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(3x^2-1581=-4x^2-6 \\ \Leftrightarrow 3x^2+4x^2=-6+1581 \\
\Leftrightarrow 7x^2 = 1575 \\
\Leftrightarrow x^2 = \frac{1575}{7}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(6x^2+0=0 \\
\Leftrightarrow 6x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{6}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(-3x^2+3)=-(-8x^2+862) \\ \Leftrightarrow 15x^2-15=8x^2-862 \\
\Leftrightarrow 15x^2-8x^2=-862+15 \\
\Leftrightarrow 7x^2 = -847 \\
\Leftrightarrow x^2 = \frac{-847}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+200=0 \\
\Leftrightarrow 2x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-9x^2-10)=-(34x^2+48) \\ \Leftrightarrow -36x^2-40=-34x^2-48 \\
\Leftrightarrow -36x^2+34x^2=-48+40 \\
\Leftrightarrow -2x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)