Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-3(-9x^2+4)=-(-32x^2+12)\)
- \(-2(-5x^2+3)=-(-14x^2+6)\)
- \(-5x^2-4=-6x^2-4\)
- \(-6x^2+145=-9x^2-2\)
- \(4(-7x^2+5)=-(33x^2-740)\)
- \(-2x^2+72=0\)
- \(2(8x^2+10)=-(-15x^2-189)\)
- \(3(10x^2+3)=-(-25x^2-29)\)
- \(-2(2x^2+6)=-(12x^2+660)\)
- \(15x^2+964=7x^2-4\)
- \(-x^2+19=6x^2-9\)
- \(5(10x^2+8)=-(-48x^2-282)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-3(-9x^2+4)=-(-32x^2+12) \\ \Leftrightarrow 27x^2-12=32x^2-12 \\
\Leftrightarrow 27x^2-32x^2=-12+12 \\
\Leftrightarrow -5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-2(-5x^2+3)=-(-14x^2+6) \\ \Leftrightarrow 10x^2-6=14x^2-6 \\
\Leftrightarrow 10x^2-14x^2=-6+6 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2-4=-6x^2-4 \\ \Leftrightarrow -5x^2+6x^2=-4+4 \\
\Leftrightarrow x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-6x^2+145=-9x^2-2 \\ \Leftrightarrow -6x^2+9x^2=-2-145 \\
\Leftrightarrow 3x^2 = -147 \\
\Leftrightarrow x^2 = \frac{-147}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(-7x^2+5)=-(33x^2-740) \\ \Leftrightarrow -28x^2+20=-33x^2+740 \\
\Leftrightarrow -28x^2+33x^2=740-20 \\
\Leftrightarrow 5x^2 = 720 \\
\Leftrightarrow x^2 = \frac{720}{5}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-2x^2+72=0 \\
\Leftrightarrow -2x^2 = -72 \\
\Leftrightarrow x^2 = \frac{-72}{-2}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(2(8x^2+10)=-(-15x^2-189) \\ \Leftrightarrow 16x^2+20=15x^2+189 \\
\Leftrightarrow 16x^2-15x^2=189-20 \\
\Leftrightarrow x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(3(10x^2+3)=-(-25x^2-29) \\ \Leftrightarrow 30x^2+9=25x^2+29 \\
\Leftrightarrow 30x^2-25x^2=29-9 \\
\Leftrightarrow 5x^2 = 20 \\
\Leftrightarrow x^2 = \frac{20}{5}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-2(2x^2+6)=-(12x^2+660) \\ \Leftrightarrow -4x^2-12=-12x^2-660 \\
\Leftrightarrow -4x^2+12x^2=-660+12 \\
\Leftrightarrow 8x^2 = -648 \\
\Leftrightarrow x^2 = \frac{-648}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(15x^2+964=7x^2-4 \\ \Leftrightarrow 15x^2-7x^2=-4-964 \\
\Leftrightarrow 8x^2 = -968 \\
\Leftrightarrow x^2 = \frac{-968}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-x^2+19=6x^2-9 \\ \Leftrightarrow -x^2-6x^2=-9-19 \\
\Leftrightarrow -7x^2 = -28 \\
\Leftrightarrow x^2 = \frac{-28}{-7}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(5(10x^2+8)=-(-48x^2-282) \\ \Leftrightarrow 50x^2+40=48x^2+282 \\
\Leftrightarrow 50x^2-48x^2=282-40 \\
\Leftrightarrow 2x^2 = 242 \\
\Leftrightarrow x^2 = \frac{242}{2}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)