Question

in a two digit number the sum of the digits is 9 .if the digits are reversed the number is increased by 9 ..find the number .linear equations in two variables​

Answer 1

Answer:

let the number= 10a+b

it's digits are reverse=10b+a

sum of the digit=a+b=9.....a=9-b

(10a+b)-(10b+a)=9

10a+b-10b-a =9

9(a-b)=9

a-b=1

a+b=9

2a=10

a=5

5-b=1

4=b

number = 54

other formula a-b=1

sum of the digit =a+b=9

a=9-b

so put the value of 'a'

9-b-b=1

2b=8

b=4

a=9-4

a=5

two digit number is 10a+b

10×5+4

54ans