Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5x^2-792=3x^2+8\)
- \(2(-2x^2-8)=-(0x^2+500)\)
- \(3(-7x^2-8)=-(22x^2+24)\)
- \(11x^2+387=3x^2-5\)
- \(-3(-10x^2-5)=-(-38x^2-143)\)
- \(-5(-8x^2+9)=-(-39x^2-36)\)
- \(-x^2-144=0\)
- \(-3x^2+44=-9x^2-10\)
- \(-x^2-4=4x^2-4\)
- \(7x^2-442=4x^2-10\)
- \(2(-3x^2+2)=-(4x^2+46)\)
- \(-4x^2+678=-8x^2+2\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5x^2-792=3x^2+8 \\ \Leftrightarrow -5x^2-3x^2=8+792 \\
\Leftrightarrow -8x^2 = 800 \\
\Leftrightarrow x^2 = \frac{800}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(-2x^2-8)=-(0x^2+500) \\ \Leftrightarrow -4x^2-16=0x^2-500 \\
\Leftrightarrow -4x^2+0x^2=-500+16 \\
\Leftrightarrow -4x^2 = -484 \\
\Leftrightarrow x^2 = \frac{-484}{-4}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(3(-7x^2-8)=-(22x^2+24) \\ \Leftrightarrow -21x^2-24=-22x^2-24 \\
\Leftrightarrow -21x^2+22x^2=-24+24 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(11x^2+387=3x^2-5 \\ \Leftrightarrow 11x^2-3x^2=-5-387 \\
\Leftrightarrow 8x^2 = -392 \\
\Leftrightarrow x^2 = \frac{-392}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(-10x^2-5)=-(-38x^2-143) \\ \Leftrightarrow 30x^2+15=38x^2+143 \\
\Leftrightarrow 30x^2-38x^2=143-15 \\
\Leftrightarrow -8x^2 = 128 \\
\Leftrightarrow x^2 = \frac{128}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(-8x^2+9)=-(-39x^2-36) \\ \Leftrightarrow 40x^2-45=39x^2+36 \\
\Leftrightarrow 40x^2-39x^2=36+45 \\
\Leftrightarrow x^2 = 81 \\
\Leftrightarrow x^2 = \frac{81}{1}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(-x^2-144=0 \\
\Leftrightarrow -x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+44=-9x^2-10 \\ \Leftrightarrow -3x^2+9x^2=-10-44 \\
\Leftrightarrow 6x^2 = -54 \\
\Leftrightarrow x^2 = \frac{-54}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2-4=4x^2-4 \\ \Leftrightarrow -x^2-4x^2=-4+4 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(7x^2-442=4x^2-10 \\ \Leftrightarrow 7x^2-4x^2=-10+442 \\
\Leftrightarrow 3x^2 = 432 \\
\Leftrightarrow x^2 = \frac{432}{3}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(2(-3x^2+2)=-(4x^2+46) \\ \Leftrightarrow -6x^2+4=-4x^2-46 \\
\Leftrightarrow -6x^2+4x^2=-46-4 \\
\Leftrightarrow -2x^2 = -50 \\
\Leftrightarrow x^2 = \frac{-50}{-2}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-4x^2+678=-8x^2+2 \\ \Leftrightarrow -4x^2+8x^2=2-678 \\
\Leftrightarrow 4x^2 = -676 \\
\Leftrightarrow x^2 = \frac{-676}{4} < 0 \\
V = \varnothing \\ -----------------\)