Answer:
option B
Step-by-step explanation:
A. [tex]3x^2 - 11x + 4 = 0[/tex]
3*4 = 12
We find out two factors whose sum is -11 and product is 12
1 times 12 = 12
To get sum -11 , then one factor should be negative. So, factoring is not possible.
B . [tex]3x^2 - 11x - 4 = 0[/tex]
3*(-4) = -12
We find out two factors whose sum is -11 and product is -12
1 times (-12) = -12
1 + (-12) = -11
So two factors are 1 and -12
Split the middle term -11x using factors 1 and -12
So equation becomes
[tex]3x^2 + 1x - 12x - 4 = 0[/tex]
Now group first two terms and last two terms
[tex](3x^2 + 1x)+ (- 12x - 4) = 0[/tex]
[tex]x(3x+ 1)-4(3x +1)=0[/tex]
(3x+1)(x-4)=0
Now we set each parenthesis =0 and solve for x
3x+1 =0 , subtract 1 on both sides
3x = -1 ( divide both sides by 3)
x= -1/3
Now we set x-4=0
add 4 on both sides
so x=4
Option B is correct
