PLS HELP AS SOON AS POSSIBLE! What is the Value of x?

What is always true when two whole numbers are subtracted?

Write the equation in logarithmic form 8^x=64

36x2 + 49y2 = 1,764 the foci are located at: (-√13, 0) and (√13,0) (0, -√13) and (0,√13) (-1, 0) and (1, 0)edit: the answer is (- the square root of 13, 0) and (the square root of 13, 0)