Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(11x^2-131=9x^2-3\)
- \(-4(6x^2-6)=-(32x^2-416)\)
- \(-3(2x^2+7)=-(10x^2+57)\)
- \(8x^2+1152=0\)
- \(5x^2-180=0\)
- \(-5(2x^2-3)=-(14x^2-15)\)
- \(-2(-3x^2-10)=-(x^2-1595)\)
- \(-3x^2+173=-8x^2-7\)
- \(2x^2-150=5x^2-3\)
- \(7x^2-31=6x^2+5\)
- \(4x^2+394=-2x^2+10\)
- \(4x^2-400=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(11x^2-131=9x^2-3 \\ \Leftrightarrow 11x^2-9x^2=-3+131 \\
\Leftrightarrow 2x^2 = 128 \\
\Leftrightarrow x^2 = \frac{128}{2}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-4(6x^2-6)=-(32x^2-416) \\ \Leftrightarrow -24x^2+24=-32x^2+416 \\
\Leftrightarrow -24x^2+32x^2=416-24 \\
\Leftrightarrow 8x^2 = 392 \\
\Leftrightarrow x^2 = \frac{392}{8}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-3(2x^2+7)=-(10x^2+57) \\ \Leftrightarrow -6x^2-21=-10x^2-57 \\
\Leftrightarrow -6x^2+10x^2=-57+21 \\
\Leftrightarrow 4x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2+1152=0 \\
\Leftrightarrow 8x^2 = -1152 \\
\Leftrightarrow x^2 = \frac{-1152}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2-180=0 \\
\Leftrightarrow 5x^2 = 180 \\
\Leftrightarrow x^2 = \frac{180}{5}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-5(2x^2-3)=-(14x^2-15) \\ \Leftrightarrow -10x^2+15=-14x^2+15 \\
\Leftrightarrow -10x^2+14x^2=15-15 \\
\Leftrightarrow 4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(-3x^2-10)=-(x^2-1595) \\ \Leftrightarrow 6x^2+20=-x^2+1595 \\
\Leftrightarrow 6x^2+x^2=1595-20 \\
\Leftrightarrow 7x^2 = 1575 \\
\Leftrightarrow x^2 = \frac{1575}{7}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-3x^2+173=-8x^2-7 \\ \Leftrightarrow -3x^2+8x^2=-7-173 \\
\Leftrightarrow 5x^2 = -180 \\
\Leftrightarrow x^2 = \frac{-180}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2-150=5x^2-3 \\ \Leftrightarrow 2x^2-5x^2=-3+150 \\
\Leftrightarrow -3x^2 = 147 \\
\Leftrightarrow x^2 = \frac{147}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2-31=6x^2+5 \\ \Leftrightarrow 7x^2-6x^2=5+31 \\
\Leftrightarrow x^2 = 36 \\
\Leftrightarrow x^2 = \frac{36}{1}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(4x^2+394=-2x^2+10 \\ \Leftrightarrow 4x^2+2x^2=10-394 \\
\Leftrightarrow 6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(4x^2-400=0 \\
\Leftrightarrow 4x^2 = 400 \\
\Leftrightarrow x^2 = \frac{400}{4}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)