Los de vierkantsvergelijking op zonder de discriminant te gebruiken
- \(-11x^2-162=-10x^2+7\)
- \(-5x^2+320=0\)
- \(-5x^2+406=-9x^2+6\)
- \(2(3x^2-2)=-(-5x^2+20)\)
- \(-6x^2-486=0\)
- \(-4(10x^2-9)=-(37x^2-36)\)
- \(-5(-7x^2+8)=-(-40x^2-140)\)
- \(-5(6x^2+8)=-(38x^2+1840)\)
- \(4(3x^2-6)=-(-20x^2+312)\)
- \(-3(4x^2-4)=-(20x^2+188)\)
- \(-4(-10x^2-4)=-(-39x^2-160)\)
- \(-4(-4x^2-4)=-(-11x^2-736)\)
Los de vierkantsvergelijking op zonder de discriminant te gebruiken
Verbetersleutel
- \(-11x^2-162=-10x^2+7 \\ \Leftrightarrow -11x^2+10x^2=7+162 \\
\Leftrightarrow -x^2 = 169 \\
\Leftrightarrow x^2 = \frac{169}{-1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5x^2+320=0 \\
\Leftrightarrow -5x^2 = -320 \\
\Leftrightarrow x^2 = \frac{-320}{-5}=64 \\
\Leftrightarrow x = 8 \vee x = -8 \\
V = \Big\{-8, 8 \Big\} \\ -----------------\)
- \(-5x^2+406=-9x^2+6 \\ \Leftrightarrow -5x^2+9x^2=6-406 \\
\Leftrightarrow 4x^2 = -400 \\
\Leftrightarrow x^2 = \frac{-400}{4} < 0 \\
V = \varnothing \\ -----------------\)
- \(2(3x^2-2)=-(-5x^2+20) \\ \Leftrightarrow 6x^2-4=5x^2-20 \\
\Leftrightarrow 6x^2-5x^2=-20+4 \\
\Leftrightarrow x^2 = -16 \\
\Leftrightarrow x^2 = \frac{-16}{1} < 0 \\
V = \varnothing \\ -----------------\)
- \(-6x^2-486=0 \\
\Leftrightarrow -6x^2 = 486 \\
\Leftrightarrow x^2 = \frac{486}{-6} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(10x^2-9)=-(37x^2-36) \\ \Leftrightarrow -40x^2+36=-37x^2+36 \\
\Leftrightarrow -40x^2+37x^2=36-36 \\
\Leftrightarrow -3x^2 = 0 \\
\Leftrightarrow x^2 = \frac{0}{-3}\\
\Leftrightarrow x = 0 \\
V = \Big\{ 0 \Big\} \\ -----------------\)
- \(-5(-7x^2+8)=-(-40x^2-140) \\ \Leftrightarrow 35x^2-40=40x^2+140 \\
\Leftrightarrow 35x^2-40x^2=140+40 \\
\Leftrightarrow -5x^2 = 180 \\
\Leftrightarrow x^2 = \frac{180}{-5} < 0 \\
V = \varnothing \\ -----------------\)
- \(-5(6x^2+8)=-(38x^2+1840) \\ \Leftrightarrow -30x^2-40=-38x^2-1840 \\
\Leftrightarrow -30x^2+38x^2=-1840+40 \\
\Leftrightarrow 8x^2 = -1800 \\
\Leftrightarrow x^2 = \frac{-1800}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(4(3x^2-6)=-(-20x^2+312) \\ \Leftrightarrow 12x^2-24=20x^2-312 \\
\Leftrightarrow 12x^2-20x^2=-312+24 \\
\Leftrightarrow -8x^2 = -288 \\
\Leftrightarrow x^2 = \frac{-288}{-8}=36 \\
\Leftrightarrow x = 6 \vee x = -6 \\
V = \Big\{-6, 6 \Big\} \\ -----------------\)
- \(-3(4x^2-4)=-(20x^2+188) \\ \Leftrightarrow -12x^2+12=-20x^2-188 \\
\Leftrightarrow -12x^2+20x^2=-188-12 \\
\Leftrightarrow 8x^2 = -200 \\
\Leftrightarrow x^2 = \frac{-200}{8} < 0 \\
V = \varnothing \\ -----------------\)
- \(-4(-10x^2-4)=-(-39x^2-160) \\ \Leftrightarrow 40x^2+16=39x^2+160 \\
\Leftrightarrow 40x^2-39x^2=160-16 \\
\Leftrightarrow x^2 = 144 \\
\Leftrightarrow x^2 = \frac{144}{1}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)
- \(-4(-4x^2-4)=-(-11x^2-736) \\ \Leftrightarrow 16x^2+16=11x^2+736 \\
\Leftrightarrow 16x^2-11x^2=736-16 \\
\Leftrightarrow 5x^2 = 720 \\
\Leftrightarrow x^2 = \frac{720}{5}=144 \\
\Leftrightarrow x = 12 \vee x = -12 \\
V = \Big\{-12, 12 \Big\} \\ -----------------\)