For this case we have the following quadratic equation:
[tex]3x ^ 2 + 21x = 0[/tex]
Dividing by 3 to both sides of the equation we have:
[tex]x ^ 2 + 7x = 0[/tex]
We take common factor "x" from the left side of the equation:
[tex]x (x + 7) = 0[/tex]
Thus, the values of "x" that satisfy equality are:
[tex]x_ {1} = 0\\x_ {2} = - 7[/tex]
Answer:
The solutions are:
[tex]x_ {1} = 0\\x_ {2} = - 7[/tex]
