Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(5(2x^2+8)=-(-16x^2+254)\)
- \(-2(6x^2+3)=-(15x^2+198)\)
- \(15x^2+9=7x^2+9\)
- \(2(5x^2-4)=-(-14x^2+24)\)
- \(-5x^2-7=-8x^2-7\)
- \(-5x^2+30=-8x^2+3\)
- \(-2(3x^2-5)=-(14x^2-298)\)
- \(-2x^2-50=0\)
- \(4x^2-676=0\)
- \(14x^2+477=8x^2-9\)
- \(2x^2+0=0\)
- \(-3x^2-1004=-10x^2+4\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(5(2x^2+8)=-(-16x^2+254) \\ \Leftrightarrow 10x^2+40=16x^2-254 \\
\Leftrightarrow 10x^2-16x^2=-254-40 \\
\Leftrightarrow -6x^2 = -294 \\
\Leftrightarrow x^2 = \frac{-294}{-6}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)
- \(-2(6x^2+3)=-(15x^2+198) \\ \Leftrightarrow -12x^2-6=-15x^2-198 \\
\Leftrightarrow -12x^2+15x^2=-198+6 \\
\Leftrightarrow 3x^2 = -192 \\
\Leftrightarrow x^2 = \frac{-192}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(15x^2+9=7x^2+9 \\ \Leftrightarrow 15x^2-7x^2=9-9 \\
\Leftrightarrow 8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(2(5x^2-4)=-(-14x^2+24) \\ \Leftrightarrow 10x^2-8=14x^2-24 \\
\Leftrightarrow 10x^2-14x^2=-24+8 \\
\Leftrightarrow -4x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{-4}=4 \\
\Leftrightarrow x = 2 \vee x = -2 \\
V = \Big\{-2, 2 \Big\} \\ -----------------\)
- \(-5x^2-7=-8x^2-7 \\ \Leftrightarrow -5x^2+8x^2=-7+7 \\
\Leftrightarrow 3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5x^2+30=-8x^2+3 \\ \Leftrightarrow -5x^2+8x^2=3-30 \\
\Leftrightarrow 3x^2 = -27 \\
\Leftrightarrow x^2 = \frac{-27}{3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-2(3x^2-5)=-(14x^2-298) \\ \Leftrightarrow -6x^2+10=-14x^2+298 \\
\Leftrightarrow -6x^2+14x^2=298-10 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-2x^2-50=0 \\
\Leftrightarrow -2x^2 = 50 \\
\Leftrightarrow x^2 = \frac{50}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(4x^2-676=0 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(14x^2+477=8x^2-9 \\ \Leftrightarrow 14x^2-8x^2=-9-477 \\
\Leftrightarrow 6x^2 = -486 \\
\Leftrightarrow x^2 = \frac{-486}{6} < 0 \\
V = \varnothing \\ -----------------\)
- \(2x^2+0=0 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3x^2-1004=-10x^2+4 \\ \Leftrightarrow -3x^2+10x^2=4+1004 \\
\Leftrightarrow 7x^2 = 1008 \\
\Leftrightarrow x^2 = \frac{1008}{7}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)