Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-2(6x^2+10)=-(10x^2+118)\)
- \(3(-6x^2+2)=-(19x^2-6)\)
- \(4(-7x^2-10)=-(30x^2+40)\)
- \(5x^2+400=10x^2-5\)
- \(2x^2-32=0\)
- \(3(2x^2-8)=-(-3x^2+699)\)
- \(-3x^2+75=0\)
- \(3(6x^2+2)=-(-20x^2+2)\)
- \(-8x^2+8=0\)
- \(13x^2-1180=6x^2+3\)
- \(13x^2+291=5x^2+3\)
- \(4(-9x^2+4)=-(31x^2+304)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-2(6x^2+10)=-(10x^2+118) \\ \Leftrightarrow -12x^2-20=-10x^2-118 \\
\Leftrightarrow -12x^2+10x^2=-118+20 \\
\Leftrightarrow -2x^2 = -98 \\
\Leftrightarrow x^2 = \frac{-98}{-2}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(3(-6x^2+2)=-(19x^2-6) \\ \Leftrightarrow -18x^2+6=-19x^2+6 \\
\Leftrightarrow -18x^2+19x^2=6-6 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4(-7x^2-10)=-(30x^2+40) \\ \Leftrightarrow -28x^2-40=-30x^2-40 \\
\Leftrightarrow -28x^2+30x^2=-40+40 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5x^2+400=10x^2-5 \\ \Leftrightarrow 5x^2-10x^2=-5-400 \\
\Leftrightarrow -5x^2 = -405 \\
\Leftrightarrow x^2 = \frac{-405}{-5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(2x^2-32=0 \\
\Leftrightarrow 2x^2 = 32 \\
\Leftrightarrow x^2 = \frac{32}{2}=16 \\
\Leftrightarrow x = 4 \vee x = -4 \\
V = \Big\{-4, 4 \Big\} \\ -----------------\)
- \(3(2x^2-8)=-(-3x^2+699) \\ \Leftrightarrow 6x^2-24=3x^2-699 \\
\Leftrightarrow 6x^2-3x^2=-699+24 \\
\Leftrightarrow 3x^2 = -675 \\
\Leftrightarrow x^2 = \frac{-675}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3x^2+75=0 \\
\Leftrightarrow -3x^2 = -75 \\
\Leftrightarrow x^2 = \frac{-75}{-3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(3(6x^2+2)=-(-20x^2+2) \\ \Leftrightarrow 18x^2+6=20x^2-2 \\
\Leftrightarrow 18x^2-20x^2=-2-6 \\
\Leftrightarrow -2x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-2}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-8x^2+8=0 \\
\Leftrightarrow -8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-8}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(13x^2-1180=6x^2+3 \\ \Leftrightarrow 13x^2-6x^2=3+1180 \\
\Leftrightarrow 7x^2 = 1183 \\
\Leftrightarrow x^2 = \frac{1183}{7}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(13x^2+291=5x^2+3 \\ \Leftrightarrow 13x^2-5x^2=3-291 \\
\Leftrightarrow 8x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-9x^2+4)=-(31x^2+304) \\ \Leftrightarrow -36x^2+16=-31x^2-304 \\
\Leftrightarrow -36x^2+31x^2=-304-16 \\
\Leftrightarrow -5x^2 = -320 \\
\Leftrightarrow x^2 = \frac{-320}{-5}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)