Question

Plz solve the 7th question soon.

Answer 1

★Heya★

Let the two digit number be xy

ACCORDING TO THE QUESTION

7 (10x + y) = 4 ( 10y + x )

=>

70x - 40y + 7y - 4x = 0

=>

66x - 33y = 0

=>

11( 6x - 3y ) = 0

=>

6x - 3y = 0

=>

y = 2x ... Equation ( i )

And

x - y = 3 ... Equation ( ii )

=>

x - 2x = 3

=>

x = - 3 And y = -6

So, the two digit number is

-36

Answer 2

Answer:

36

Step-by-step explanation:

Let the digit at unit's place be x and the digit at ten's place be y.

⇒ Therefore, the given number is 10y + x    ------- (*)

Given that digits are reversed.

Digit at unit's place = y.

Digit at ten's place = x.

∴ Reversed number = 10x + y.

According to the given condition,

⇒ 7(10y + x) = 4(10x + y)

⇒ 70y + 7x = 40x + 4y

⇒ 66y = 33x

⇒ 2y - x = 0

Now,

Given that difference of the digits is 3 {x > y}

x - y = 3

On solving (i) & (ii), we get

2y - x = 0

-y + x = 3

------------------

y = 3

Substitute y = 3 in (i), we get

⇒ 2y - x = 0

⇒ 6 - x = 0

⇒ x = 6

Substitute in (*), we get

⇒ 10y + x = 10(3) + 6

                = 36

∴ The number is 36.

Hope it helps!