Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-x^2-336=6x^2+7\)
- \(-2(2x^2+9)=-(8x^2-46)\)
- \(2(3x^2-8)=-(-2x^2-384)\)
- \(3x^2-300=0\)
- \(-x^2+0=0\)
- \(6x^2+131=7x^2+10\)
- \(-12x^2-989=-7x^2-9\)
- \(-5x^2+560=2x^2-7\)
- \(-3(-6x^2-7)=-(-10x^2-13)\)
- \(-2x^2+1178=5x^2-5\)
- \(-8x^2+1800=0\)
- \(3x^2+55=5x^2+5\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-x^2-336=6x^2+7 \\ \Leftrightarrow -x^2-6x^2=7+336 \\
\Leftrightarrow -7x^2 = 343 \\
\Leftrightarrow x^2 = \frac{343}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(2x^2+9)=-(8x^2-46) \\ \Leftrightarrow -4x^2-18=-8x^2+46 \\
\Leftrightarrow -4x^2+8x^2=46+18 \\
\Leftrightarrow 4x^2 = 64 \\
\Leftrightarrow x^2 = \frac{64}{4}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(2(3x^2-8)=-(-2x^2-384) \\ \Leftrightarrow 6x^2-16=2x^2+384 \\
\Leftrightarrow 6x^2-2x^2=384+16 \\
\Leftrightarrow 4x^2 = 400 \\
\Leftrightarrow x^2 = \frac{400}{4}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(3x^2-300=0 \\
\Leftrightarrow 3x^2 = 300 \\
\Leftrightarrow x^2 = \frac{300}{3}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-x^2+0=0 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(6x^2+131=7x^2+10 \\ \Leftrightarrow 6x^2-7x^2=10-131 \\
\Leftrightarrow -x^2 = -121 \\
\Leftrightarrow x^2 = \frac{-121}{-1}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-12x^2-989=-7x^2-9 \\ \Leftrightarrow -12x^2+7x^2=-9+989 \\
\Leftrightarrow -5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2+560=2x^2-7 \\ \Leftrightarrow -5x^2-2x^2=-7-560 \\
\Leftrightarrow -7x^2 = -567 \\
\Leftrightarrow x^2 = \frac{-567}{-7}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-3(-6x^2-7)=-(-10x^2-13) \\ \Leftrightarrow 18x^2+21=10x^2+13 \\
\Leftrightarrow 18x^2-10x^2=13-21 \\
\Leftrightarrow 8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2+1178=5x^2-5 \\ \Leftrightarrow -2x^2-5x^2=-5-1178 \\
\Leftrightarrow -7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{-7}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-8x^2+1800=0 \\
\Leftrightarrow -8x^2 = -1800 \\
\Leftrightarrow x^2 = \frac{-1800}{-8}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(3x^2+55=5x^2+5 \\ \Leftrightarrow 3x^2-5x^2=5-55 \\
\Leftrightarrow -2x^2 = -50 \\
\Leftrightarrow x^2 = \frac{-50}{-2}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)