Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(5x^2-10)=-(17x^2+462)\)
- \(5(-6x^2+3)=-(38x^2-23)\)
- \(7x^2+343=0\)
- \(5x^2+125=0\)
- \(-7x^2+448=0\)
- \(-10x^2+14=-7x^2+2\)
- \(-6x^2+384=0\)
- \(x^2-53=6x^2-8\)
- \(6x^2-1350=0\)
- \(-4(2x^2+9)=-(3x^2-944)\)
- \(3x^2-286=-3x^2+8\)
- \(-10x^2-190=-2x^2+10\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(5x^2-10)=-(17x^2+462) \\ \Leftrightarrow -25x^2+50=-17x^2-462 \\
\Leftrightarrow -25x^2+17x^2=-462-50 \\
\Leftrightarrow -8x^2 = -512 \\
\Leftrightarrow x^2 = \frac{-512}{-8}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(5(-6x^2+3)=-(38x^2-23) \\ \Leftrightarrow -30x^2+15=-38x^2+23 \\
\Leftrightarrow -30x^2+38x^2=23-15 \\
\Leftrightarrow 8x^2 = 8 \\
\Leftrightarrow x^2 = \frac{8}{8}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(7x^2+343=0 \\
\Leftrightarrow 7x^2 = -343 \\
\Leftrightarrow x^2 = \frac{-343}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2+125=0 \\
\Leftrightarrow 5x^2 = -125 \\
\Leftrightarrow x^2 = \frac{-125}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-7x^2+448=0 \\
\Leftrightarrow -7x^2 = -448 \\
\Leftrightarrow x^2 = \frac{-448}{-7}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-10x^2+14=-7x^2+2 \\ \Leftrightarrow -10x^2+7x^2=2-14 \\
\Leftrightarrow -3x^2 = -12 \\
\Leftrightarrow x^2 = \frac{-12}{-3}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-6x^2+384=0 \\
\Leftrightarrow -6x^2 = -384 \\
\Leftrightarrow x^2 = \frac{-384}{-6}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(x^2-53=6x^2-8 \\ \Leftrightarrow x^2-6x^2=-8+53 \\
\Leftrightarrow -5x^2 = 45 \\
\Leftrightarrow x^2 = \frac{45}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-1350=0 \\
\Leftrightarrow 6x^2 = 1350 \\
\Leftrightarrow x^2 = \frac{1350}{6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(-4(2x^2+9)=-(3x^2-944) \\ \Leftrightarrow -8x^2-36=-3x^2+944 \\
\Leftrightarrow -8x^2+3x^2=944+36 \\
\Leftrightarrow -5x^2 = 980 \\
\Leftrightarrow x^2 = \frac{980}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(3x^2-286=-3x^2+8 \\ \Leftrightarrow 3x^2+3x^2=8+286 \\
\Leftrightarrow 6x^2 = 294 \\
\Leftrightarrow x^2 = \frac{294}{6}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-10x^2-190=-2x^2+10 \\ \Leftrightarrow -10x^2+2x^2=10+190 \\
\Leftrightarrow -8x^2 = 200 \\
\Leftrightarrow x^2 = \frac{200}{-8} < 0 \\
V = \varnothing \\ -----------------\)