Find A Remainder
1. The problem states that when the polynomial $$4x^3 - 6x + ax + 3$$ is divided by $$2x - 1$$, the remainder is 7.
2. By the Remainder Theorem, the remainder of a polynomial $$f(x)$$ when divided by $$2x - 1$$ is equal to $$f\left(\frac{1}{2}\right)$$.
3. We substitute $$x = \frac{1}{2}$$ into the polynomial:
$$f\left(\frac{1}{2}\right) = 4\left(\frac{1}{2}\right)^3 - 6\left(\frac{1}{2}\right) + a\left(\frac{1}{2}\right) + 3$$
4. Simplify each term:
$$4 \times \frac{1}{8} = \frac{4}{8} = \frac{1}{2}$$
$$-6 \times \frac{1}{2} = -3$$
$$a \times \frac{1}{2} = \frac{a}{2}$$
5. So,
$$f\left(\frac{1}{2}\right) = \frac{1}{2} - 3 + \frac{a}{2} + 3 = \frac{1}{2} + \frac{a}{2}$$
6. According to the problem, this value must be equal to 7:
$$\frac{1}{2} + \frac{a}{2} = 7$$
7. Subtract $$\frac{1}{2}$$ from both sides:
$$\frac{a}{2} = 7 - \frac{1}{2} = \frac{14}{2} - \frac{1}{2} = \frac{13}{2}$$
8. Multiply both sides by 2:
$$a = 13$$
**Final answer:** $$a = 13$$