i dont understand this

Answer:
x = 8.3 is the value of x.
Step-by-step explanation:
Given:
Let Δ ABC be a Right angle Triangle at ∠ C = 90°
AB = x
BC = 6
m∠ B = 44°
To Find:
x = ?
Solution:
We apply Cosine Rule
{tex}\cos B = \frac{\textrm{side Adjacent to angle B}}{Hypotenuse} \\{/tex]
Substituting the given values we get
[tex]\cos B = \frac{BC}{AB}\\\\\cos 44 = \frac{6}{x}\\\\0.719=\frac{6}{x}\\\\\therefore x=\frac{6}{0.719} \\\\\therefore x=8.3......(nearest\ tenth)[/tex]
The value of x is
x = 8.3