Question

• The sum of the digits of a two digit number is 12
if 18 is added to it, the digits
digits are reversed. Find
the number​

Answer 1

▶⏩ Let the unit digit be x,

=> and , tens digit be y.

→A/Q

↪➡ x + y = 12. .....................(1).

=> The real number is x + 10y.

=> And the reversed number is 10x + y.

▶⏩Now,

↪➡ x + 10y + 18 = 10x + y.

↪➡ 10y - y + 18 = 10x -x.

↪➡ 9y + 18 = 9x.

↪➡ 18 = 9x - 9y.

↪➡ 9x - 9y = 18.

↪➡ 9( x - y ) = 18.

↪➡ x - y = 18/9.

↪➡ x - y = 2. ......................(2)

 ▶⏩ Add in equation (1) and (2).

↪➡ x + y + x - y = 12 + 2.

↪➡ 2x = 14.

↪➡ x = 14/2.

→ x = 7.

=> put the value of ‘x’ in equation (2).

↪➡ 7 - y = 2.

↪➡ -y = 2 - 7.

→ y = 5.

▶⏩ Hence, the obtained number is:-)

↪➡ x + 10y.

= 7 + 10 × 5.

= 57.

Answer 2

Answer:

57

Step-by-step explanation:

suppose the number is 10a+b,it's obvious a>2 since a+b=12

As 10a+b+18=10*b+a

So 9(b-a)=18

b-a=2

Also a+b=12 ,so a=5,b=7