Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-5(-5x^2-3)=-(-19x^2-9)\)
- \(9x^2+97=8x^2-3\)
- \(16x^2+185=9x^2+10\)
- \(-2x^2+236=3x^2-9\)
- \(-3x^2+75=0\)
- \(-8x^2+1352=0\)
- \(-6x^2-726=0\)
- \(5(-8x^2+3)=-(43x^2-90)\)
- \(8x^2-151=7x^2-7\)
- \(-3(2x^2-5)=-(14x^2+1337)\)
- \(-4(10x^2+5)=-(34x^2-994)\)
- \(3(-6x^2+7)=-(25x^2+546)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-5(-5x^2-3)=-(-19x^2-9) \\ \Leftrightarrow 25x^2+15=19x^2+9 \\
\Leftrightarrow 25x^2-19x^2=9-15 \\
\Leftrightarrow 6x^2 = -6 \\
\Leftrightarrow x^2 = \frac{-6}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(9x^2+97=8x^2-3 \\ \Leftrightarrow 9x^2-8x^2=-3-97 \\
\Leftrightarrow x^2 = -100 \\
\Leftrightarrow x^2 = \frac{-100}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(16x^2+185=9x^2+10 \\ \Leftrightarrow 16x^2-9x^2=10-185 \\
\Leftrightarrow 7x^2 = -175 \\
\Leftrightarrow x^2 = \frac{-175}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2+236=3x^2-9 \\ \Leftrightarrow -2x^2-3x^2=-9-236 \\
\Leftrightarrow -5x^2 = -245 \\
\Leftrightarrow x^2 = \frac{-245}{-5}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-3x^2+75=0 \\
\Leftrightarrow -3x^2 = -75 \\
\Leftrightarrow x^2 = \frac{-75}{-3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-8x^2+1352=0 \\
\Leftrightarrow -8x^2 = -1352 \\
\Leftrightarrow x^2 = \frac{-1352}{-8}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-6x^2-726=0 \\
\Leftrightarrow -6x^2 = 726 \\
\Leftrightarrow x^2 = \frac{726}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(5(-8x^2+3)=-(43x^2-90) \\ \Leftrightarrow -40x^2+15=-43x^2+90 \\
\Leftrightarrow -40x^2+43x^2=90-15 \\
\Leftrightarrow 3x^2 = 75 \\
\Leftrightarrow x^2 = \frac{75}{3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(8x^2-151=7x^2-7 \\ \Leftrightarrow 8x^2-7x^2=-7+151 \\
\Leftrightarrow x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{1}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-3(2x^2-5)=-(14x^2+1337) \\ \Leftrightarrow -6x^2+15=-14x^2-1337 \\
\Leftrightarrow -6x^2+14x^2=-1337-15 \\
\Leftrightarrow 8x^2 = -1352 \\
\Leftrightarrow x^2 = \frac{-1352}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(10x^2+5)=-(34x^2-994) \\ \Leftrightarrow -40x^2-20=-34x^2+994 \\
\Leftrightarrow -40x^2+34x^2=994+20 \\
\Leftrightarrow -6x^2 = 1014 \\
\Leftrightarrow x^2 = \frac{1014}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(3(-6x^2+7)=-(25x^2+546) \\ \Leftrightarrow -18x^2+21=-25x^2-546 \\
\Leftrightarrow -18x^2+25x^2=-546-21 \\
\Leftrightarrow 7x^2 = -567 \\
\Leftrightarrow x^2 = \frac{-567}{7} < 0 \\
V = \varnothing \\ -----------------\)