I don’t get number seven someone help

Answer:
1 1/9 =x
Step-by-step explanation:
x+2x+3x+4x
----------------------- =9
x*x
10x
-------=9
x^2
10
----=9
x
10 = 9x
10/9 =x
1 1/9 =x
Step-by-step explanation:
[tex]\frac{x + 2x + 3x + 4x}{x . x\\}[/tex] = 9
=> [tex]\frac{10x}{x^{2} }[/tex] = 9
=> [tex]\frac{10}{x}[/tex] = 9
=> x = [tex]\frac{10}{9}[/tex]
And answer (C) 1 [tex]\frac{1}{9}[/tex] = [tex]\frac{10}{9}[/tex] = x