Answer:
x = 0, -4 and -3.
Step-by-step explanation:
The given expression is "3x to the power of 3 + 21x squared + 36x = 0".
We can write this expression as follows :
[tex]3x^3+21x^2+36x=0[/tex]
Taking 3x common.
[tex]3x(x^2+7x+12)=0\\\\3x=0\ \text{and}\ (x^2+7x+12)=0[/tex]
x = 3
[tex]x^2+7x+12=0\\\\x^2+3x+4x+12=0\\\\x(x+3)+4(x+3)=0\\\\(x+4)(x+3)=0\\\\x=-4,-3[/tex]
Hence, the solution of the given quadratic equation are x = 0, -4 and -3.
