Evaluate A
1. **State the problem:** We are given the polynomial $$4x^3 - 6x + ax + 3$$ and told that when it is divided by $$2x - 1$$, the remainder is 7.
2. **Understand the divisor:** First, we set $$2x - 1 = 0$$ to find the value of $$x$$ at which the remainder is evaluated. From $$2x - 1 = 0$$, we get $$x = \frac{1}{2}$$.
3. **Apply the Remainder Theorem:** The remainder when a polynomial $$f(x)$$ is divided by $$x - c$$ is $$f(c)$$. Since the divisor is $$2x - 1$$, replace $$x$$ with $$\frac{1}{2}$$ in the polynomial and set the expression equal to 7:
$$4\left(\frac{1}{2}\right)^3 - 6\left(\frac{1}{2}\right) + a\left(\frac{1}{2}\right) + 3 = 7$$
4. **Simplify each term:**
$$4\left(\frac{1}{8}\right) - 3 + \frac{a}{2} + 3 = 7$$
$$\frac{4}{8} - 3 + \frac{a}{2} + 3 = 7$$
$$\frac{1}{2} + \frac{a}{2} = 7$$
5. **Combine like terms:**
$$\frac{1}{2} + \frac{a}{2} = 7$$
Multiply both sides by 2 to clear the denominator:
$$1 + a = 14$$
6. **Solve for $$a$$:**
$$a = 14 - 1 = 13$$
**Final answer:** $$a = 13$$