Question

in a two digits number X both the sum and difference of its digits is 4 . the value of x is?

Answer 1

Step-by-step explanation:

Let the digit in the ones place be x and tens place be y

Hence the two digit number =10y+x

Given that the two digit number =4 times sum of its digits

According to the question,

⇒ 10y+x=4(x+y)

⇒ 10y+x=4x+4y

⇒ 3x−6y=0

⇒ x=2y ------- ( 1 )

It is also given that the two digit number =2 times product of its digits

⇒ 10y+x=2xy

Divide by xy both the sides, we get

⇒ 10/x + 1/y = 2

Put x=2y from (1), we get

⇒ 10/2y +1/y

y = 3

x=2y=2(3)=6

⇒ The two digit number =(10y+x)=10(3)+6=36

Answer 2

Answer:

x = 40

Step-by-step explanation:

Let a and b be the two digits of x,

So that 10a+b = 4.

Given that a + b = 4 and a - b = 4,

adding those two equations gives

   a + b = 4

+ a - b = 4

   2a = 8

or a = 4.

Subtracting the two equations yields

   a + b = 4

- a -(+) b = (-)4

        2b = 0

or -2b = 0

so that b = 0.

Thus x = 40