Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(9x^2+2)=-(41x^2+586)\)
- \(-2x^2-8=0\)
- \(2(3x^2+6)=-(-x^2+233)\)
- \(3x^2+588=0\)
- \(-7x^2+1183=0\)
- \(5(-3x^2+8)=-(21x^2-904)\)
- \(-3x^2+70=2x^2-10\)
- \(6x^2+486=0\)
- \(3(-2x^2+9)=-(9x^2-174)\)
- \(-5x^2+0=0\)
- \(5x^2+23=-2x^2-5\)
- \(8x^2+8=0\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(9x^2+2)=-(41x^2+586) \\ \Leftrightarrow -45x^2-10=-41x^2-586 \\
\Leftrightarrow -45x^2+41x^2=-586+10 \\
\Leftrightarrow -4x^2 = -576 \\
\Leftrightarrow x^2 = \frac{-576}{-4}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-2x^2-8=0 \\
\Leftrightarrow -2x^2 = 8 \\
\Leftrightarrow x^2 = \frac{8}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(3x^2+6)=-(-x^2+233) \\ \Leftrightarrow 6x^2+12=x^2-233 \\
\Leftrightarrow 6x^2-x^2=-233-12 \\
\Leftrightarrow 5x^2 = -245 \\
\Leftrightarrow x^2 = \frac{-245}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2+588=0 \\
\Leftrightarrow 3x^2 = -588 \\
\Leftrightarrow x^2 = \frac{-588}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-7x^2+1183=0 \\
\Leftrightarrow -7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{-7}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(5(-3x^2+8)=-(21x^2-904) \\ \Leftrightarrow -15x^2+40=-21x^2+904 \\
\Leftrightarrow -15x^2+21x^2=904-40 \\
\Leftrightarrow 6x^2 = 864 \\
\Leftrightarrow x^2 = \frac{864}{6}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-3x^2+70=2x^2-10 \\ \Leftrightarrow -3x^2-2x^2=-10-70 \\
\Leftrightarrow -5x^2 = -80 \\
\Leftrightarrow x^2 = \frac{-80}{-5}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(6x^2+486=0 \\
\Leftrightarrow 6x^2 = -486 \\
\Leftrightarrow x^2 = \frac{-486}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(-2x^2+9)=-(9x^2-174) \\ \Leftrightarrow -6x^2+27=-9x^2+174 \\
\Leftrightarrow -6x^2+9x^2=174-27 \\
\Leftrightarrow 3x^2 = 147 \\
\Leftrightarrow x^2 = \frac{147}{3}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-5x^2+0=0 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2+23=-2x^2-5 \\ \Leftrightarrow 5x^2+2x^2=-5-23 \\
\Leftrightarrow 7x^2 = -28 \\
\Leftrightarrow x^2 = \frac{-28}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(8x^2+8=0 \\
\Leftrightarrow 8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{8} < 0 \\
V = \varnothing \\ -----------------\)