Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-9x^2+396=-4x^2-9\)
- \(2x^2-338=0\)
- \(-4x^2+256=0\)
- \(-2x^2+128=3x^2+3\)
- \(3(2x^2+4)=-(-14x^2-4)\)
- \(2(2x^2-3)=-(3x^2-246)\)
- \(-13x^2+674=-9x^2-2\)
- \(-5x^2+845=0\)
- \(-10x^2+160=-9x^2-9\)
- \(-x^2+36=0\)
- \(-12x^2+1366=-5x^2-6\)
- \(-2(-10x^2-9)=-(-22x^2+432)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-9x^2+396=-4x^2-9 \\ \Leftrightarrow -9x^2+4x^2=-9-396 \\
\Leftrightarrow -5x^2 = -405 \\
\Leftrightarrow x^2 = \frac{-405}{-5}=81 \\
\Leftrightarrow x = 9 \vee x = -9 \\
V = \Big\{-9, 9 \Big\} \\ -----------------\)
- \(2x^2-338=0 \\
\Leftrightarrow 2x^2 = 338 \\
\Leftrightarrow x^2 = \frac{338}{2}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-4x^2+256=0 \\
\Leftrightarrow -4x^2 = -256 \\
\Leftrightarrow x^2 = \frac{-256}{-4}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-2x^2+128=3x^2+3 \\ \Leftrightarrow -2x^2-3x^2=3-128 \\
\Leftrightarrow -5x^2 = -125 \\
\Leftrightarrow x^2 = \frac{-125}{-5}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(3(2x^2+4)=-(-14x^2-4) \\ \Leftrightarrow 6x^2+12=14x^2+4 \\
\Leftrightarrow 6x^2-14x^2=4-12 \\
\Leftrightarrow -8x^2 = -8 \\
\Leftrightarrow x^2 = \frac{-8}{-8}=1 \\
\Leftrightarrow x = 1 \vee x = -1 \\
V = \Big\{-1, 1 \Big\} \\ -----------------\)
- \(2(2x^2-3)=-(3x^2-246) \\ \Leftrightarrow 4x^2-6=-3x^2+246 \\
\Leftrightarrow 4x^2+3x^2=246+6 \\
\Leftrightarrow 7x^2 = 252 \\
\Leftrightarrow x^2 = \frac{252}{7}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-13x^2+674=-9x^2-2 \\ \Leftrightarrow -13x^2+9x^2=-2-674 \\
\Leftrightarrow -4x^2 = -676 \\
\Leftrightarrow x^2 = \frac{-676}{-4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-5x^2+845=0 \\
\Leftrightarrow -5x^2 = -845 \\
\Leftrightarrow x^2 = \frac{-845}{-5}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-10x^2+160=-9x^2-9 \\ \Leftrightarrow -10x^2+9x^2=-9-160 \\
\Leftrightarrow -x^2 = -169 \\
\Leftrightarrow x^2 = \frac{-169}{-1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-x^2+36=0 \\
\Leftrightarrow -x^2 = -36 \\
\Leftrightarrow x^2 = \frac{-36}{-1}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-12x^2+1366=-5x^2-6 \\ \Leftrightarrow -12x^2+5x^2=-6-1366 \\
\Leftrightarrow -7x^2 = -1372 \\
\Leftrightarrow x^2 = \frac{-1372}{-7}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(-2(-10x^2-9)=-(-22x^2+432) \\ \Leftrightarrow 20x^2+18=22x^2-432 \\
\Leftrightarrow 20x^2-22x^2=-432-18 \\
\Leftrightarrow -2x^2 = -450 \\
\Leftrightarrow x^2 = \frac{-450}{-2}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)