Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-4x^2-100=0\)
- \(11x^2-8=8x^2-5\)
- \(3x^2-7=6x^2-10\)
- \(-3(-6x^2-6)=-(-14x^2-274)\)
- \(5(6x^2-10)=-(-23x^2-293)\)
- \(5x^2-980=0\)
- \(-4(3x^2-2)=-(14x^2+10)\)
- \(-2x^2-521=-10x^2-9\)
- \(-5x^2-180=0\)
- \(x^2+34=9x^2+2\)
- \(4(7x^2-6)=-(-20x^2+24)\)
- \(4x^2-144=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-4x^2-100=0 \\
\Leftrightarrow -4x^2 = 100 \\
\Leftrightarrow x^2 = \frac{100}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(11x^2-8=8x^2-5 \\ \Leftrightarrow 11x^2-8x^2=-5+8 \\
\Leftrightarrow 3x^2 = 3 \\
\Leftrightarrow x^2 = \frac{3}{3}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(3x^2-7=6x^2-10 \\ \Leftrightarrow 3x^2-6x^2=-10+7 \\
\Leftrightarrow -3x^2 = -3 \\
\Leftrightarrow x^2 = \frac{-3}{-3}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(-3(-6x^2-6)=-(-14x^2-274) \\ \Leftrightarrow 18x^2+18=14x^2+274 \\
\Leftrightarrow 18x^2-14x^2=274-18 \\
\Leftrightarrow 4x^2 = 256 \\
\Leftrightarrow x^2 = \frac{256}{4}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(5(6x^2-10)=-(-23x^2-293) \\ \Leftrightarrow 30x^2-50=23x^2+293 \\
\Leftrightarrow 30x^2-23x^2=293+50 \\
\Leftrightarrow 7x^2 = 343 \\
\Leftrightarrow x^2 = \frac{343}{7}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(5x^2-980=0 \\
\Leftrightarrow 5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{5}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-4(3x^2-2)=-(14x^2+10) \\ \Leftrightarrow -12x^2+8=-14x^2-10 \\
\Leftrightarrow -12x^2+14x^2=-10-8 \\
\Leftrightarrow 2x^2 = -18 \\
\Leftrightarrow x^2 = \frac{-18}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2-521=-10x^2-9 \\ \Leftrightarrow -2x^2+10x^2=-9+521 \\
\Leftrightarrow 8x^2 = 512 \\
\Leftrightarrow x^2 = \frac{512}{8}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-5x^2-180=0 \\
\Leftrightarrow -5x^2 = 180 \\
\Leftrightarrow x^2 = \frac{180}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(x^2+34=9x^2+2 \\ \Leftrightarrow x^2-9x^2=2-34 \\
\Leftrightarrow -8x^2 = -32 \\
\Leftrightarrow x^2 = \frac{-32}{-8}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(4(7x^2-6)=-(-20x^2+24) \\ \Leftrightarrow 28x^2-24=20x^2-24 \\
\Leftrightarrow 28x^2-20x^2=-24+24 \\
\Leftrightarrow 8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4x^2-144=0 \\
\Leftrightarrow 4x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{4}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)