Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(4x^2+197=7x^2+5\)
- \(2x^2-1345=-6x^2+7\)
- \(6x^2-1350=0\)
- \(x^2-25=0\)
- \(-2(-5x^2-6)=-(-9x^2-181)\)
- \(-3(-5x^2+6)=-(-13x^2+306)\)
- \(-14x^2+390=-10x^2-10\)
- \(-3(-10x^2-2)=-(-22x^2-6)\)
- \(11x^2+8=6x^2+8\)
- \(3(-2x^2+4)=-(-x^2+51)\)
- \(-3(-10x^2-5)=-(-28x^2-15)\)
- \(5(8x^2+7)=-(-38x^2-133)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(4x^2+197=7x^2+5 \\ \Leftrightarrow 4x^2-7x^2=5-197 \\
\Leftrightarrow -3x^2 = -192 \\
\Leftrightarrow x^2 = \frac{-192}{-3}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(2x^2-1345=-6x^2+7 \\ \Leftrightarrow 2x^2+6x^2=7+1345 \\
\Leftrightarrow 8x^2 = 1352 \\
\Leftrightarrow x^2 = \frac{1352}{8}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(6x^2-1350=0 \\
\Leftrightarrow 6x^2 = 1350 \\
\Leftrightarrow x^2 = \frac{1350}{6}=225 \\
\Leftrightarrow x = 15 \vee x = -15 \\
V = \Big\{-15, 15 \Big\} \\ -----------------\)
- \(x^2-25=0 \\
\Leftrightarrow x^2 = 25 \\
\Leftrightarrow x^2 = \frac{25}{1}=25 \\
\Leftrightarrow x = 5 \vee x = -5 \\
V = \Big\{-5, 5 \Big\} \\ -----------------\)
- \(-2(-5x^2-6)=-(-9x^2-181) \\ \Leftrightarrow 10x^2+12=9x^2+181 \\
\Leftrightarrow 10x^2-9x^2=181-12 \\
\Leftrightarrow x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{1}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-3(-5x^2+6)=-(-13x^2+306) \\ \Leftrightarrow 15x^2-18=13x^2-306 \\
\Leftrightarrow 15x^2-13x^2=-306+18 \\
\Leftrightarrow 2x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{2} < 0 \\
V = \varnothing \\ -----------------\)
- \(-14x^2+390=-10x^2-10 \\ \Leftrightarrow -14x^2+10x^2=-10-390 \\
\Leftrightarrow -4x^2 = -400 \\
\Leftrightarrow x^2 = \frac{-400}{-4}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-3(-10x^2-2)=-(-22x^2-6) \\ \Leftrightarrow 30x^2+6=22x^2+6 \\
\Leftrightarrow 30x^2-22x^2=6-6 \\
\Leftrightarrow 8x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{8}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(11x^2+8=6x^2+8 \\ \Leftrightarrow 11x^2-6x^2=8-8 \\
\Leftrightarrow 5x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{5}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(3(-2x^2+4)=-(-x^2+51) \\ \Leftrightarrow -6x^2+12=x^2-51 \\
\Leftrightarrow -6x^2-x^2=-51-12 \\
\Leftrightarrow -7x^2 = -63 \\
\Leftrightarrow x^2 = \frac{-63}{-7}=9 \\
\Leftrightarrow x = 3 \vee x = -3 \\
V = \Big\{-3, 3 \Big\} \\ -----------------\)
- \(-3(-10x^2-5)=-(-28x^2-15) \\ \Leftrightarrow 30x^2+15=28x^2+15 \\
\Leftrightarrow 30x^2-28x^2=15-15 \\
\Leftrightarrow 2x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{2}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(5(8x^2+7)=-(-38x^2-133) \\ \Leftrightarrow 40x^2+35=38x^2+133 \\
\Leftrightarrow 40x^2-38x^2=133-35 \\
\Leftrightarrow 2x^2 = 98 \\
\Leftrightarrow x^2 = \frac{98}{2}=49 \\
\Leftrightarrow x = 7 \vee x = -7 \\
V = \Big\{-7, 7 \Big\} \\ -----------------\)