Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-3(-2x^2+7)=-(-10x^2+5)\)
- \(12x^2-1362=4x^2-10\)
- \(-5x^2+13=-6x^2+9\)
- \(2(4x^2+5)=-(-11x^2-685)\)
- \(11x^2+313=6x^2-7\)
- \(7x^2-175=0\)
- \(5(-2x^2+4)=-(3x^2+323)\)
- \(5(6x^2-8)=-(-33x^2+28)\)
- \(5x^2-674=9x^2+2\)
- \(6x^2-1176=0\)
- \(-2x^2+450=0\)
- \(4(-2x^2-3)=-(2x^2-138)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-3(-2x^2+7)=-(-10x^2+5) \\ \Leftrightarrow 6x^2-21=10x^2-5 \\
\Leftrightarrow 6x^2-10x^2=-5+21 \\
\Leftrightarrow -4x^2 = 16 \\
\Leftrightarrow x^2 = \frac{16}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(12x^2-1362=4x^2-10 \\ \Leftrightarrow 12x^2-4x^2=-10+1362 \\
\Leftrightarrow 8x^2 = 1352 \\
\Leftrightarrow x^2 = \frac{1352}{8}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-5x^2+13=-6x^2+9 \\ \Leftrightarrow -5x^2+6x^2=9-13 \\
\Leftrightarrow x^2 = -4 \\
\Leftrightarrow x^2 = \frac{-4}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(4x^2+5)=-(-11x^2-685) \\ \Leftrightarrow 8x^2+10=11x^2+685 \\
\Leftrightarrow 8x^2-11x^2=685-10 \\
\Leftrightarrow -3x^2 = 675 \\
\Leftrightarrow x^2 = \frac{675}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(11x^2+313=6x^2-7 \\ \Leftrightarrow 11x^2-6x^2=-7-313 \\
\Leftrightarrow 5x^2 = -320 \\
\Leftrightarrow x^2 = \frac{-320}{5} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2-175=0 \\
\Leftrightarrow 7x^2 = 175 \\
\Leftrightarrow x^2 = \frac{175}{7}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(5(-2x^2+4)=-(3x^2+323) \\ \Leftrightarrow -10x^2+20=-3x^2-323 \\
\Leftrightarrow -10x^2+3x^2=-323-20 \\
\Leftrightarrow -7x^2 = -343 \\
\Leftrightarrow x^2 = \frac{-343}{-7}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(5(6x^2-8)=-(-33x^2+28) \\ \Leftrightarrow 30x^2-40=33x^2-28 \\
\Leftrightarrow 30x^2-33x^2=-28+40 \\
\Leftrightarrow -3x^2 = 12 \\
\Leftrightarrow x^2 = \frac{12}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(5x^2-674=9x^2+2 \\ \Leftrightarrow 5x^2-9x^2=2+674 \\
\Leftrightarrow -4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{-4} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-1176=0 \\
\Leftrightarrow 6x^2 = 1176 \\
\Leftrightarrow x^2 = \frac{1176}{6}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-2x^2+450=0 \\
\Leftrightarrow -2x^2 = -450 \\
\Leftrightarrow x^2 = \frac{-450}{-2}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(4(-2x^2-3)=-(2x^2-138) \\ \Leftrightarrow -8x^2-12=-2x^2+138 \\
\Leftrightarrow -8x^2+2x^2=138+12 \\
\Leftrightarrow -6x^2 = 150 \\
\Leftrightarrow x^2 = \frac{150}{-6} < 0 \\
V = \varnothing \\ -----------------\)