Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-2x^2-72=0\)
- \(7x^2+1183=0\)
- \(5(5x^2+7)=-(-24x^2-179)\)
- \(x^2-282=-7x^2+6\)
- \(2(8x^2+3)=-(-18x^2+282)\)
- \(-5(6x^2+10)=-(27x^2-382)\)
- \(-5(2x^2+6)=-(6x^2+30)\)
- \(4(8x^2+2)=-(-28x^2-684)\)
- \(-2(9x^2+4)=-(13x^2+988)\)
- \(4x^2-400=0\)
- \(-x^2+0=0\)
- \(-3x^2-105=-6x^2+3\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-2x^2-72=0 \\
\Leftrightarrow -2x^2 = 72 \\
\Leftrightarrow x^2 = \frac{72}{-2} < 0 \\
V = \varnothing \\ -----------------\)
- \(7x^2+1183=0 \\
\Leftrightarrow 7x^2 = -1183 \\
\Leftrightarrow x^2 = \frac{-1183}{7} < 0 \\
V = \varnothing \\ -----------------\)
- \(5(5x^2+7)=-(-24x^2-179) \\ \Leftrightarrow 25x^2+35=24x^2+179 \\
\Leftrightarrow 25x^2-24x^2=179-35 \\
\Leftrightarrow x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{1}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(x^2-282=-7x^2+6 \\ \Leftrightarrow x^2+7x^2=6+282 \\
\Leftrightarrow 8x^2 = 288 \\
\Leftrightarrow x^2 = \frac{288}{8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(2(8x^2+3)=-(-18x^2+282) \\ \Leftrightarrow 16x^2+6=18x^2-282 \\
\Leftrightarrow 16x^2-18x^2=-282-6 \\
\Leftrightarrow -2x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{-2}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-5(6x^2+10)=-(27x^2-382) \\ \Leftrightarrow -30x^2-50=-27x^2+382 \\
\Leftrightarrow -30x^2+27x^2=382+50 \\
\Leftrightarrow -3x^2 = 432 \\
\Leftrightarrow x^2 = \frac{432}{-3} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(2x^2+6)=-(6x^2+30) \\ \Leftrightarrow -10x^2-30=-6x^2-30 \\
\Leftrightarrow -10x^2+6x^2=-30+30 \\
\Leftrightarrow -4x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-4}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(4(8x^2+2)=-(-28x^2-684) \\ \Leftrightarrow 32x^2+8=28x^2+684 \\
\Leftrightarrow 32x^2-28x^2=684-8 \\
\Leftrightarrow 4x^2 = 676 \\
\Leftrightarrow x^2 = \frac{676}{4}=169 \\
\Leftrightarrow x = 13 \vee x = -13 \\
V = \Big\{-13, 13 \Big\} \\ -----------------\)
- \(-2(9x^2+4)=-(13x^2+988) \\ \Leftrightarrow -18x^2-8=-13x^2-988 \\
\Leftrightarrow -18x^2+13x^2=-988+8 \\
\Leftrightarrow -5x^2 = -980 \\
\Leftrightarrow x^2 = \frac{-980}{-5}=196 \\
\Leftrightarrow x = 14 \vee x = -14 \\
V = \Big\{-14, 14 \Big\} \\ -----------------\)
- \(4x^2-400=0 \\
\Leftrightarrow 4x^2 = 400 \\
\Leftrightarrow x^2 = \frac{400}{4}=100 \\
\Leftrightarrow x = 10 \vee x = -10 \\
V = \Big\{-10, 10 \Big\} \\ -----------------\)
- \(-x^2+0=0 \\
\Leftrightarrow -x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-1}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-3x^2-105=-6x^2+3 \\ \Leftrightarrow -3x^2+6x^2=3+105 \\
\Leftrightarrow 3x^2 = 108 \\
\Leftrightarrow x^2 = \frac{108}{3}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)