Question

. A number consists of two digits whose sum is 8. If 18 is added to the number its digits are reversed. Find the number.

Answer 1

Answer:

-181

Let the ones place no. be x and tens place no.be y;no.=10x+y

A to q

x+y=8

10x+y+18=10y+x

=9x-9y=-18

=x-y=-2

x=y-2

putting the value of x =y-2

x+y=8

y-2+y=8

2y-2=8

y-1=4

y=5

x=3

The no. is 35

Answer 2

Answer:

Let the ten digit no. be x

and the one digit no. be y

According to the question

x+y = 8 ( equation 1)

10x+y+18=10y+× (equation 2)

10x+y-10y-×=-18

9x-9y=-18

x-y=-2 (equation 2)

Let equation 2

x=-2+y

putting this value into equation 1

(-2+y)+y=8

2y=10

y=5

Therefore,

x=-2+y

x=-2+5

x=3

so,the no. be

35