The value of the sine of angle x does not change when a triangle is dilated. The sine function, which is the ratio of the side opposite the angle to the hypotenuse, remains the same regardless of the size of the triangle.
Since the original sine of angle x is given as \( \frac{4}{5} \), the sine of angle x for the dilated triangle will also be \( \frac{4}{5} \).
So, the answer for Blank 1 is:
\(\frac{4}{5}\)