Answer:
x ≈ 15.3
Step-by-step explanation:
Based on the pythagoras theorem
[tex]a^{2} + b^{2} = c^{2}[/tex]
Since the legs are "5x" and "x" we know the following....
[tex](5x)^{2} + x^{2} = 78^{2} \\25x^{2} + x^{2} = 6084\\26x^{2} = 6084\\x^{2} = 234\\x = \sqrt{234} \\x = 15.3[/tex]
(This is round did to the nearest tenth)
