Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(6x^2-10)=-(-37x^2+50)\)
- \(-5(10x^2+4)=-(56x^2-34)\)
- \(-2x^2-100=-4x^2-2\)
- \(-6x^2+726=0\)
- \(2(2x^2-8)=-(-9x^2+621)\)
- \(5(-5x^2+4)=-(18x^2+92)\)
- \(-14x^2+4=-10x^2+4\)
- \(-5(8x^2+6)=-(39x^2+30)\)
- \(5x^2-845=0\)
- \(-2x^2+43=2x^2+7\)
- \(-2(9x^2+8)=-(20x^2+34)\)
- \(-3(4x^2-10)=-(19x^2-373)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(6x^2-10)=-(-37x^2+50) \\ \Leftrightarrow 30x^2-50=37x^2-50 \\
\Leftrightarrow 30x^2-37x^2=-50+50 \\
\Leftrightarrow -7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(10x^2+4)=-(56x^2-34) \\ \Leftrightarrow -50x^2-20=-56x^2+34 \\
\Leftrightarrow -50x^2+56x^2=34+20 \\
\Leftrightarrow 6x^2 = 54 \\
\Leftrightarrow x^2 = \frac{54}{6}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-2x^2-100=-4x^2-2 \\ \Leftrightarrow -2x^2+4x^2=-2+100 \\
\Leftrightarrow 2x^2 = 98 \\
\Leftrightarrow x^2 = \frac{98}{2}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-6x^2+726=0 \\
\Leftrightarrow -6x^2 = -726 \\
\Leftrightarrow x^2 = \frac{-726}{-6}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(2(2x^2-8)=-(-9x^2+621) \\ \Leftrightarrow 4x^2-16=9x^2-621 \\
\Leftrightarrow 4x^2-9x^2=-621+16 \\
\Leftrightarrow -5x^2 = -605 \\
\Leftrightarrow x^2 = \frac{-605}{-5}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(5(-5x^2+4)=-(18x^2+92) \\ \Leftrightarrow -25x^2+20=-18x^2-92 \\
\Leftrightarrow -25x^2+18x^2=-92-20 \\
\Leftrightarrow -7x^2 = -112 \\
\Leftrightarrow x^2 = \frac{-112}{-7}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(-14x^2+4=-10x^2+4 \\ \Leftrightarrow -14x^2+10x^2=4-4 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(8x^2+6)=-(39x^2+30) \\ \Leftrightarrow -40x^2-30=-39x^2-30 \\
\Leftrightarrow -40x^2+39x^2=-30+30 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2-845=0 \\
\Leftrightarrow 5x^2 = 845 \\
\Leftrightarrow x^2 = \frac{845}{5}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-2x^2+43=2x^2+7 \\ \Leftrightarrow -2x^2-2x^2=7-43 \\
\Leftrightarrow -4x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{-4}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-2(9x^2+8)=-(20x^2+34) \\ \Leftrightarrow -18x^2-16=-20x^2-34 \\
\Leftrightarrow -18x^2+20x^2=-34+16 \\
\Leftrightarrow 2x^2 = -18 \\
\Leftrightarrow x^2 = \frac{-18}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(4x^2-10)=-(19x^2-373) \\ \Leftrightarrow -12x^2+30=-19x^2+373 \\
\Leftrightarrow -12x^2+19x^2=373-30 \\
\Leftrightarrow 7x^2 = 343 \\
\Leftrightarrow x^2 = \frac{343}{7}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)