Question

Answer please...... ..........

Answer 1

Let the digit at units place be x and the digit at tens place be y.

So, the no.=(10y+x)

According to question,

(10y+x)=(10x+y)+9

10y+x=10x+y+9

9x-9y=-9

x-y=-1 ----------------(1)

Also, given that,

x+y=9 ----------------(2)

(1)+(2)

2x=8

[x=4]

Put x=4 in (1),

4-y=-1

[y=5]

So, the no.=10×5+4

=50+4

=54