1. **State the problem:** We are given the equation $$(3x - d)^2 = ax^2 - 3kx + 49$$ and need to find the values of $a$, $k$, and $d$.
2. **Expand the left side:** Use the formula for the square of a binomial $$(A - B)^2 = A^2 - 2AB + B^2$$.
$$ (3x - d)^2 = (3x)^2 - 2 \cdot 3x \cdot d + d^2 = 9x^2 - 6dx + d^2 $$
3. **Match coefficients:** The expanded form must equal the right side:
$$ 9x^2 - 6dx + d^2 = ax^2 - 3kx + 49 $$
Equate coefficients of like terms:
- Coefficient of $x^2$: $9 = a$
- Coefficient of $x$: $-6d = -3k$ which simplifies to $6d = 3k$ or $k = 2d$
- Constant term: $d^2 = 49$
4. **Solve for $d$:**
$$ d^2 = 49 \implies d = \pm 7 $$
5. **Find $k$ using $k = 2d$:**
- If $d = 7$, then $k = 2 \times 7 = 14$
- If $d = -7$, then $k = 2 \times (-7) = -14$
6. **Final values:**
$$ a = 9 $$
$$ d = \pm 7 $$
$$ k = \pm 14 $$
The values of $a$, $k$, and $d$ satisfy the given equation with $d$ and $k$ having two possible sign pairs.
Find A K D
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