Question

a number consists of two digits whose sum is 7 . If 45 is added to the number the digits are reversed find the number​

Answer 1

Answer:

16

x=1, y= 6

Step-by-step explanation:

let the digit at tens digit be x

and the digit at units place be y

therefore, the number = 10x + y

according to first condition,

x + y = 7......eqn(1)

according to second condition,

10x + y + 45 = 10y + x

10y - y + x - 10x = 45

-9x + 9y = 45

dividing by 9 on both side

-x + y = 5............eqn (2)

adding eqn 1 and 2

x + y = 7

-x + y = 5

2y = 12

y = 12/2

y = 6

substituting y = 6 in eqn 1

x + 6 = 7

x = 7 - 6

x = 1

thereftherefore original number =

10x + y = 10 + 6

= 16

( x , y) = (1,6)