1. **State the problem.**
We need to solve the equation $a^3+a^2=36$ and find $a$.
2. **Rewrite the equation in standard form.**
Move everything to one side:
$$a^3+a^2-36=0$$
3. **Look for an integer root.**
Since $36$ is a small number, test simple integer values.
Try $a=3$:
$$3^3+3^2=27+9=36$$
So $a=3$ is a solution.
4. **Factor using the known root.**
Because $a=3$ works, $(a-3)$ is a factor:
$$a^3+a^2-36=(a-3)(a^2+4a+12)$$
So the equation becomes:
$$ (a-3)(a^2+4a+12)=0 $$
5. **Set each factor equal to zero.**
From $(a-3)=0$:
$$a=3$$
6. **Check the quadratic factor.**
Solve $a^2+4a+12=0$ using the discriminant:
$$b^2-4ac=4^2-4(1)(12)=16-48=-32$$
Since the discriminant is negative, this quadratic has no real solutions.
7. **Final answer.**
The real solution is:
$$a=3$$
Cubic Equation Dfddaf
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.