Answer:
[tex]x=-4\pm2\sqrt{6}[/tex]
Step-by-step explanation:
Completing the square for quadratic in the form [tex]ax^2+bx+c=0[/tex]
Given equation:
[tex]3x^2+24x-24=0[/tex]
Factor out 3:
[tex]\implies 3(x^2+8x-8)=0[/tex]
Divide both sides by 3:
[tex]\implies x^2+8x-8=0[/tex]
Add 8 to both sides:
[tex]\implies x^2+8x=8[/tex]
[tex]\textsf{Add }\: \left(\dfrac{b}{2}\right)^2\: \textsf{ to both sides}:[/tex]
[tex]\implies x^2+8x+\left(\dfrac{8}{2}\right)^2=8+\left(\dfrac{8}{2}\right)^2[/tex]
[tex]\implies x^2+8x+16=8+16[/tex]
[tex]\implies x^2+8x+16=24[/tex]
Factor the left side:
[tex]\implies (x+4)^2=24[/tex]
Square root both sides:
[tex]\implies x+4=\pm2\sqrt{6}[/tex]
Subtract 4 from both sides:
[tex]\implies x=-4\pm2\sqrt{6}[/tex]
