Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-8x^2-800=0\)
- \(6x^2-973=-2x^2-5\)
- \(-7x^2+63=0\)
- \(-3(-2x^2-9)=-(-9x^2+0)\)
- \(-3x^2+164=-2x^2-5\)
- \(2(-7x^2+4)=-(11x^2-11)\)
- \(-2x^2+128=0\)
- \(-4(-6x^2-8)=-(-27x^2-539)\)
- \(-3(6x^2+7)=-(19x^2+37)\)
- \(-2x^2-15=-9x^2-8\)
- \(3(2x^2+3)=-(-9x^2+66)\)
- \(-18x^2+202=-10x^2+2\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-8x^2-800=0 \\
\Leftrightarrow -8x^2 = 800 \\
\Leftrightarrow x^2 = \frac{800}{-8} < 0 \\
V = \varnothing \\ -----------------\)
- \(6x^2-973=-2x^2-5 \\ \Leftrightarrow 6x^2+2x^2=-5+973 \\
\Leftrightarrow 8x^2 = 968 \\
\Leftrightarrow x^2 = \frac{968}{8}=121 \\
\Leftrightarrow x = 11 \vee x = -11 \\
V = \Big\{-11, 11 \Big\} \\ -----------------\)
- \(-7x^2+63=0 \\
\Leftrightarrow -7x^2 = -63 \\
\Leftrightarrow x^2 = \frac{-63}{-7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-3(-2x^2-9)=-(-9x^2+0) \\ \Leftrightarrow 6x^2+27=9x^2+0 \\
\Leftrightarrow 6x^2-9x^2=0-27 \\
\Leftrightarrow -3x^2 = -27 \\
\Leftrightarrow x^2 = \frac{-27}{-3}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-3x^2+164=-2x^2-5 \\ \Leftrightarrow -3x^2+2x^2=-5-164 \\
\Leftrightarrow -x^2 = -169 \\
\Leftrightarrow x^2 = \frac{-169}{-1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(2(-7x^2+4)=-(11x^2-11) \\ \Leftrightarrow -14x^2+8=-11x^2+11 \\
\Leftrightarrow -14x^2+11x^2=11-8 \\
\Leftrightarrow -3x^2 = 3 \\
\Leftrightarrow x^2 = \frac{3}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2+128=0 \\
\Leftrightarrow -2x^2 = -128 \\
\Leftrightarrow x^2 = \frac{-128}{-2}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-4(-6x^2-8)=-(-27x^2-539) \\ \Leftrightarrow 24x^2+32=27x^2+539 \\
\Leftrightarrow 24x^2-27x^2=539-32 \\
\Leftrightarrow -3x^2 = 507 \\
\Leftrightarrow x^2 = \frac{507}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-3(6x^2+7)=-(19x^2+37) \\ \Leftrightarrow -18x^2-21=-19x^2-37 \\
\Leftrightarrow -18x^2+19x^2=-37+21 \\
\Leftrightarrow x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2x^2-15=-9x^2-8 \\ \Leftrightarrow -2x^2+9x^2=-8+15 \\
\Leftrightarrow 7x^2 = 7 \\
\Leftrightarrow x^2 = \frac{7}{7}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(3(2x^2+3)=-(-9x^2+66) \\ \Leftrightarrow 6x^2+9=9x^2-66 \\
\Leftrightarrow 6x^2-9x^2=-66-9 \\
\Leftrightarrow -3x^2 = -75 \\
\Leftrightarrow x^2 = \frac{-75}{-3}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-18x^2+202=-10x^2+2 \\ \Leftrightarrow -18x^2+10x^2=2-202 \\
\Leftrightarrow -8x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{-8}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)