Verified Answer :

  • To solve \(-2|x - 4| + 7 = -3\), isolate the absolute value to get \(|x - 4| = 5\), which leads to the solutions \(x = 9\) and \(x = -1\).
  • To solve \(v = 7x - 3w\) for \(x\), add \(3w\) to both sides and divide by \(7\) to obtain \(x = \frac{v + 3w}{7}\).
  • Final answers: \(x = -1, 9\) and \(x = \frac{v + 3w}{7}\). \(\boxed{x = -1, 9; \quad x = \frac{v + 3w}{7}}\)

Explanation

  1. Analysis of the Problems

We are asked to solve two distinct problems. The first problem is to find the values of \(x\) that satisfy the absolute value equation \(-2|x - 4| + 7 = -3\). The second problem is to solve the linear equation \(v = 7x - 3w\) for \(x\). We will address each problem separately using standard algebraic manipulation techniques.

  1. Solving the Absolute Value Equation

To solve \(-2|x - 4| + 7 = -3\), we first isolate the absolute value term.
Subtract \(7\) from both sides:
\[-2|x - 4| = -3 - 7\]
\[-2|x - 4| = -10\]
Next, divide both sides by \(-2\):
\[|x - 4| = \frac{-10}{-2}\]
\[|x - 4| = 5\]
Now, we consider the definition of the absolute value, which gives us two cases:
Case 1: \(x - 4 = 5\)
Adding \(4\) to both sides, we get:
\[x = 5 + 4 = 9\]
Case 2: \(x - 4 = -5\)
Adding \(4\) to both sides, we get:
\[x = -5 + 4 = -1\]
Thus, the solutions are \(x = 9\) and \(x = -1\).

  1. Solving for \(x\) in terms of \(v\) and \(w\)

To solve \(v = 7x - 3w\) for \(x\), we need to isolate \(x\) on one side of the equation.
Start with the given equation:
\[v = 7x - 3w\]
Add \(3w\) to both sides:
\[v + 3w = 7x\]
Finally, divide both sides by \(7\) to solve for \(x\):
\[x = \frac{v + 3w}{7}\]
This gives us the expression for \(x\) in terms of \(v\) and \(w\).

Examples

The ability to manipulate equations and solve for variables is foundational to many real-world applications. For instance, in physics, a formula like \(d = v_0 t + \frac{1}{2}at^2\) relates distance, velocity, time, and acceleration. Solving this for time or acceleration requires the same algebraic isolation techniques used here. Similarly, in economics, a budget constraint equation \(I = p_1x_1 + p_2x_2\) can be rearranged to find the quantity of one good \(x_1\) in terms of the price of both goods and the other quantity \(x_2\). Mastery of these operations ensures that you can rearrange any physical or economic model to solve for the specific variable you need.