Question

sum of the digits of a two digit number is 12.if 18 added to it, the digits are reversed. find the number.
please solve it according to class 8th with one variable and with full steps ​

Answer 1

Let the number be x y

x=ten's place

y=units place

x+y=12-------(1)

10x+y is the number

10x+y+18=10y+x

10x-x+y-10y= -18

9x-9y= -18

9(x-y)= -18

x-y= -18/2

x-y = -2----------(2)

Adding equation(1)&(2)

2x=12-2

2x=10

x=10/2

x=5

x+y=12

=>5+y=12

=>y=12-5

=>y=7

So the number is 57 .

hope this helps you

:)