Question

a two digit number is 7 times the sum of its digit. if the difference between two digit is 2, find the number ​

Answer 1

Answer:

Let the two digits are x,y

The number Obtained= 10x+y

In question

10x+y=7(x+y)

10x+y=7x+7y

10x+y-7x-7y=0

3x-6y=0

3(x-2y)=0

x-2y=0------(1)

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

(-) (+)=(-)

Substracting these two equation we get

-2y+y=0-2

-y=-2

y=2

Putting Y=2 in equation (2) we get

x-y=2

x-2=2

x=2+2=4

x=4

The number is 10x+y=10*4+2=40+2=42