Question

The sum of the digit of 2 digit number is 7 if the
digit are reversed, the new number is increased by 3
less than 4 times the orginal number find the
Orginal no.​

Answer 1

Answer:

16 (or 61 when reversed)

Step-by-step explanation:

Let the 2-digit number be 10x + y with x and y as the two individual digits.

Then,

x + y = 7--------eq.1

(10y + x) = 4(10x + y)-3

=40x + 4y -3

40x - x = 10y -4y + 3

39x -6y -3 = 0

On dividing throughout by 3,

13x - 2y- 1=0 -----eq.2

Multiply eq.1 by 2,

2x + 2y - 14 = 0-------eq.3

{eq.2+eq.3}

15x = 15

x = 1

x + y = 7

==> y = 6

The question is find the original no. i.e.

10x + y = 16.

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Hope it helps....!

♧♤♧

Answer 2

Answer:

61

Step-by-step explanation:

x+y=7

x=7-y

10x+y=4(10y+x)-3

10x+y=40y+4x-3

10x-4x=40y-y-3

6x=39y-3

2x=13y-1

2(7-y)=13y-1

14-2y+1=13y

15=15y

y=1

x=6

Original no.=10x+y

10*6+1=61