How do you solve using the completing the square method 0=3x^2-2x-12?
1 Answer
Jul 11, 2017
Explanation:
"require the coefficient of " x^2" term to be unity"
rArr3(x^2-2/3x-4)=0
"to complete the square" add
(1/2"coefficient of the x-term")^2" to " x^2-2/3x
3(x^2-2/3xcolor(red)(+1/9)color(magenta)(-1/9)-4)=0
"we must also subtract " 1/9
rArr3((x-1/3)^2-37/9)=0
"distributing gives"
3(x-1/3)^2-37/3=0
rArr(x-1/3)^2=37/9
color(blue)"take the square root of both sides"
rArrx-1/3=+-sqrt(37/9)larr" note plus or minus"
"add "1/3" to both sides"
rArrx=1/3+-sqrt37/3
