Answer:
-4
Step-by-step explanation:
The given equation is
[tex]3x(x+4)=66[/tex]
On simplification we get
[tex]3x^2+12x=66[/tex]
Divide both sides by 3.
[tex]x^2+4x=22[/tex]
[tex]x^2+4x-22=0[/tex]
If a quadratic equation is defined as [tex]ax^2+bx+c=0[/tex], then the sum of solutions is -b/a.
In the above equation a=1, b=4 and c=-22.
Sum of solutions [tex]=-\dfrac{b}{a}=-\dfrac{4}{1}=-4[/tex]
Therefore, the sum of all solutions is -4.
