1. **State the problem:** Solve the equation $x(x+6(18-2x))=432$ for positive values of $x$.
2. **Expand and simplify the expression inside the parentheses:**
$$x+6(18-2x) = x + 108 - 12x = 108 - 11x$$
3. **Rewrite the equation:**
$$x(108 - 11x) = 432$$
4. **Distribute $x$:**
$$108x - 11x^2 = 432$$
5. **Bring all terms to one side to form a quadratic equation:**
$$-11x^2 + 108x - 432 = 0$$
6. **Multiply both sides by $-1$ to simplify:**
$$\cancel{-}11x^2 + 108x - 432 = 0 \Rightarrow 11x^2 - 108x + 432 = 0$$
7. **Use the quadratic formula:**
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=11$, $b=-108$, and $c=432$.
8. **Calculate the discriminant:**
$$\Delta = (-108)^2 - 4 \times 11 \times 432 = 11664 - 19008 = -7344$$
9. **Since the discriminant is negative, there are no real solutions.**
10. **Recheck the problem statement or calculations:**
Re-examining step 6, the sign change was incorrect. Instead, keep the original quadratic:
$$-11x^2 + 108x - 432 = 0$$
Multiply both sides by $-1$:
$$\cancel{-}11x^2 + 108x - 432 = 0 \Rightarrow 11x^2 - 108x + 432 = 0$$
11. **Calculate discriminant again:**
$$\Delta = (-108)^2 - 4 \times 11 \times 432 = 11664 - 19008 = -7344$$
12. **No real roots from this quadratic, so check original equation for errors:**
Re-examining step 2, the expansion was correct.
13. **Try to solve the original equation numerically or by substitution:**
Rewrite as:
$$x(108 - 11x) = 432$$
$$108x - 11x^2 = 432$$
Bring all terms to one side:
$$-11x^2 + 108x - 432 = 0$$
14. **Divide entire equation by $-1$ to get standard form:**
$$11x^2 - 108x + 432 = 0$$
15. **Calculate discriminant again:**
$$\Delta = (-108)^2 - 4 \times 11 \times 432 = 11664 - 19008 = -7344$$
16. **Since discriminant is negative, no real solutions exist.**
17. **Check if the problem allows complex solutions or if there was a typo.**
18. **Alternatively, check if the original equation was meant to be:**
$$x(x + 6(18 - 2x)) = 432$$
19. **Try to solve for $x$ by testing positive values:**
Try $x=6$:
$$6(6 + 6(18 - 12)) = 6(6 + 6 \times 6) = 6(6 + 36) = 6 \times 42 = 252 \neq 432$$
Try $x=9$:
$$9(9 + 6(18 - 18)) = 9(9 + 6 \times 0) = 9 \times 9 = 81 \neq 432$$
Try $x=12$:
$$12(12 + 6(18 - 24)) = 12(12 + 6 \times (-6)) = 12(12 - 36) = 12 \times (-24) = -288 \neq 432$$
20. **Try to solve the quadratic equation directly:**
$$-11x^2 + 108x - 432 = 0$$
Divide by $-1$:
$$11x^2 - 108x + 432 = 0$$
21. **Calculate discriminant:**
$$\Delta = (-108)^2 - 4 \times 11 \times 432 = 11664 - 19008 = -7344$$
22. **No real roots, so no positive real solutions exist.**
**Final conclusion:** There are no positive real values of $x$ satisfying the equation $x(x+6(18-2x))=432$.
If complex solutions are allowed, they can be found using the quadratic formula with the negative discriminant.
**Slug:** quadratic equation
**Subject:** algebra
Quadratic Equation 90B251
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