To find the modulus of a complex number, we use the formula:
|a + bi| = √(a^2 + b^2)
Given 6 - 4i as our complex number, we substitute a = 6 and b = -4 into the formula:
|6 - 4i| = √(6^2 + (-4)^2)
|6 - 4i| = √(36 + 16)
|6 - 4i| = √52
Therefore, the modulus of 6 - 4i is √52.