Question

In a two digit number the units place digit is x if the sum of digits be 9 then the number is (10 x- 9)​

Answer 1

Answer:

(10x-9)=9

(10x)=9+9(because -9 when added to left side its value changes and become 9)(

Answer 2

tens digit=9-x

then the number is = 10(9-x)+x

= 90-10x+x

= 90-9x

= 9(10-x)