1. **Problem Statement:** Find the values of $x$ such that the area of the triangle with vertices $(x,4)$, $(2,-6)$, and $(5,4)$ is 35 square units.
2. **Formula for Area of Triangle with Coordinates:**
The area $A$ of a triangle with vertices $(x_1,y_1)$, $(x_2,y_2)$, and $(x_3,y_3)$ is given by:
$$
A = \frac{1}{2} \left| x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2) \right|
$$
3. **Substitute the given points:**
Let $(x_1,y_1) = (x,4)$, $(x_2,y_2) = (2,-6)$, $(x_3,y_3) = (5,4)$.
Calculate the expression inside the absolute value:
$$
x( -6 - 4 ) + 2(4 - 4) + 5(4 - (-6)) = x(-10) + 2(0) + 5(10) = -10x + 50
$$
4. **Set up the area equation:**
$$
35 = \frac{1}{2} | -10x + 50 |
$$
Multiply both sides by 2:
$$
70 = | -10x + 50 |
$$
5. **Solve the absolute value equation:**
$$
-10x + 50 = 70 \quad \text{or} \quad -10x + 50 = -70
$$
For the first case:
$$
-10x + 50 = 70 \\ -10x = 20 \\ x = \frac{20}{-10} = -2
$$
For the second case:
$$
-10x + 50 = -70 \\ -10x = -120 \\ x = \frac{-120}{-10} = 12
$$
6. **Final answer:** The values of $x$ are $12$ and $-2$.
**Answer choice:** (a) 12, −2
Triangle Area X D75A17
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