Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4(-6x^2+5)=-(-23x^2+45)\)
- \(-13x^2+837=-6x^2-10\)
- \(4(7x^2-9)=-(-22x^2-1140)\)
- \(-5x^2+0=0\)
- \(2x^2-8=0\)
- \(-10x^2-9=-2x^2-9\)
- \(-2x^2-18=0\)
- \(-3(3x^2+4)=-(11x^2-20)\)
- \(7x^2-343=0\)
- \(3x^2-192=0\)
- \(2(6x^2+3)=-(-5x^2-118)\)
- \(-2(-6x^2-5)=-(-13x^2-10)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4(-6x^2+5)=-(-23x^2+45) \\ \Leftrightarrow 24x^2-20=23x^2-45 \\
\Leftrightarrow 24x^2-23x^2=-45+20 \\
\Leftrightarrow x^2 = -25 \\
\Leftrightarrow x^2 = \frac{-25}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-13x^2+837=-6x^2-10 \\ \Leftrightarrow -13x^2+6x^2=-10-837 \\
\Leftrightarrow -7x^2 = -847 \\
\Leftrightarrow x^2 = \frac{-847}{-7}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(4(7x^2-9)=-(-22x^2-1140) \\ \Leftrightarrow 28x^2-36=22x^2+1140 \\
\Leftrightarrow 28x^2-22x^2=1140+36 \\
\Leftrightarrow 6x^2 = 1176 \\
\Leftrightarrow x^2 = \frac{1176}{6}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-5x^2+0=0 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(2x^2-8=0 \\
\Leftrightarrow 2x^2 = 8 \\
\Leftrightarrow x^2 = \frac{8}{2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-10x^2-9=-2x^2-9 \\ \Leftrightarrow -10x^2+2x^2=-9+9 \\
\Leftrightarrow -8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2x^2-18=0 \\
\Leftrightarrow -2x^2 = 18 \\
\Leftrightarrow x^2 = \frac{18}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(3x^2+4)=-(11x^2-20) \\ \Leftrightarrow -9x^2-12=-11x^2+20 \\
\Leftrightarrow -9x^2+11x^2=20+12 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(7x^2-343=0 \\
\Leftrightarrow 7x^2 = 343 \\
\Leftrightarrow x^2 = \frac{343}{7}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(3x^2-192=0 \\
\Leftrightarrow 3x^2 = 192 \\
\Leftrightarrow x^2 = \frac{192}{3}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(2(6x^2+3)=-(-5x^2-118) \\ \Leftrightarrow 12x^2+6=5x^2+118 \\
\Leftrightarrow 12x^2-5x^2=118-6 \\
\Leftrightarrow 7x^2 = 112 \\
\Leftrightarrow x^2 = \frac{112}{7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-2(-6x^2-5)=-(-13x^2-10) \\ \Leftrightarrow 12x^2+10=13x^2+10 \\
\Leftrightarrow 12x^2-13x^2=10-10 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)