Question: The table shows two values of $x$ and their corresponding values of $y$. The graph of the linear equation representing this relationship passes through the point $\left(\frac{1}{4}, a\right)$. What is the value of $a$?
1. **State the problem:** We are given two points from a table: $(-12, -45)$ and $(6, 45)$, and we know the graph of the linear equation passes through $\left(\frac{1}{4}, a\right)$. We need to find the value of $a$.
2. **Find the slope $m$ of the line:** The slope formula is $$m = \frac{y_2 - y_1}{x_2 - x_1}.$$ Using the points $(-12, -45)$ and $(6, 45)$:
$$m = \frac{45 - (-45)}{6 - (-12)} = \frac{45 + 45}{6 + 12} = \frac{90}{18} = 5.$$
3. **Write the equation of the line:** Using the slope-intercept form $y = mx + b$, substitute $m=5$ and use one point to find $b$.
Using point $(-12, -45)$:
$$-45 = 5(-12) + b$$
$$-45 = -60 + b$$
$$b = -45 + 60 = 15.$$
So the equation is:
$$y = 5x + 15.$$
4. **Find $a$ when $x = \frac{1}{4}$:** Substitute $x = \frac{1}{4}$ into the equation:
$$a = 5 \times \frac{1}{4} + 15 = \frac{5}{4} + 15 = \frac{5}{4} + \frac{60}{4} = \frac{65}{4}.$$
**Final answer:**
$$a = \frac{65}{4}.$$