Find the angle between the two planes `2x + y 2z = 5`and `3x 6y 2z = 7`using vector method.

Explanation

To find the angle between the two planes given by the equations \(2x + y - 2z = 5\) and \(3x - 6y - 2z = 7\) using the vector method, we can follow these steps:

### Step 1: Identify the normal vectors of the planes
The normal vector of a plane given by the equation \(Ax + By + Cz = D\) is \(\vec{n} = (A, B, C)\).

For the first plane \(2x + y - 2z = 5\):
- The coefficients are \(A = 2\), \(B = 1\), \(C = -2\).
- Thus, the normal vector \(\vec{n_1} = (2, 1, -2)\).
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