Respuesta :

Answer: Lets find a common denominator that will be 90 because 9x10 is 90

and 10x9 is 90.   so now multiply the numerator so that will 9x9 is 81 so 81/90 then 7/9x10 is 70/90  

then just subtract

81-70 is 11 so its 11/90

Step-by-step explanation: