Find `|veca|and |vecb|, if (veca+vecb).(veca-vecb) =8 and |veca|=8|vecb|`

Explanation

To solve the problem, we need to find the magnitudes of the vectors \(\vec{a}\) and \(\vec{b}\) given the equations:

1. \((\vec{a} + \vec{b}) \cdot (\vec{a} - \vec{b}) = 8\)
2. \(|\vec{a}| = 8 |\vec{b}|\)

### Step-by-step Solution:

**Step 1: Expand the dot product.**
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