Find the angle between two planes given by `3x+ 4y -5 z = 6 and 5x + 10 y - 20 z = 14`. Using
vector method.

Explanation

To find the angle between the two planes given by the equations \(3x + 4y - 5z = 6\) and \(5x + 10y - 20z = 14\) 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 \(\vec{n} = Ai + Bj + Ck\).

For the first plane \(3x + 4y - 5z = 6\):
- The normal vector \(\vec{n_1} = 3i + 4j - 5k\).

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