Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(11x^2-261=7x^2-5\)
- \(4x^2-255=-3x^2-3\)
- \(-3x^2-507=0\)
- \(5(-10x^2+6)=-(43x^2-478)\)
- \(3x^2-411=-2x^2-6\)
- \(-3x^2-6=-8x^2-6\)
- \(-x^2-64=0\)
- \(-2(-10x^2+8)=-(-19x^2-33)\)
- \(-9x^2+1130=-4x^2+5\)
- \(4(5x^2+9)=-(-13x^2+1147)\)
- \(3x^2-315=7x^2+9\)
- \(-5(-6x^2+5)=-(-37x^2+25)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(11x^2-261=7x^2-5 \\ \Leftrightarrow 11x^2-7x^2=-5+261 \\
\Leftrightarrow 4x^2 = 256 \\
\Leftrightarrow x^2 = \frac{256}{4}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(4x^2-255=-3x^2-3 \\ \Leftrightarrow 4x^2+3x^2=-3+255 \\
\Leftrightarrow 7x^2 = 252 \\
\Leftrightarrow x^2 = \frac{252}{7}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-3x^2-507=0 \\
\Leftrightarrow -3x^2 = 507 \\
\Leftrightarrow x^2 = \frac{507}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(5(-10x^2+6)=-(43x^2-478) \\ \Leftrightarrow -50x^2+30=-43x^2+478 \\
\Leftrightarrow -50x^2+43x^2=478-30 \\
\Leftrightarrow -7x^2 = 448 \\
\Leftrightarrow x^2 = \frac{448}{-7} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2-411=-2x^2-6 \\ \Leftrightarrow 3x^2+2x^2=-6+411 \\
\Leftrightarrow 5x^2 = 405 \\
\Leftrightarrow x^2 = \frac{405}{5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-3x^2-6=-8x^2-6 \\ \Leftrightarrow -3x^2+8x^2=-6+6 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-x^2-64=0 \\
\Leftrightarrow -x^2 = 64 \\
\Leftrightarrow x^2 = \frac{64}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(-10x^2+8)=-(-19x^2-33) \\ \Leftrightarrow 20x^2-16=19x^2+33 \\
\Leftrightarrow 20x^2-19x^2=33+16 \\
\Leftrightarrow x^2 = 49 \\
\Leftrightarrow x^2 = \frac{49}{1}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-9x^2+1130=-4x^2+5 \\ \Leftrightarrow -9x^2+4x^2=5-1130 \\
\Leftrightarrow -5x^2 = -1125 \\
\Leftrightarrow x^2 = \frac{-1125}{-5}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(4(5x^2+9)=-(-13x^2+1147) \\ \Leftrightarrow 20x^2+36=13x^2-1147 \\
\Leftrightarrow 20x^2-13x^2=-1147-36 \\
\Leftrightarrow 7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2-315=7x^2+9 \\ \Leftrightarrow 3x^2-7x^2=9+315 \\
\Leftrightarrow -4x^2 = 324 \\
\Leftrightarrow x^2 = \frac{324}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(-6x^2+5)=-(-37x^2+25) \\ \Leftrightarrow 30x^2-25=37x^2-25 \\
\Leftrightarrow 30x^2-37x^2=-25+25 \\
\Leftrightarrow -7x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-7}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)