Question

A two-digit number is 7 times the sum of its digits. The number formed by

reversing the digits is 18 less than the original number. Find the number. ​

Answer 1

let the digits be x and y.... so number is 10x + y

so as given in ques. , 10x+y = 7(x+y)

3x - 6y = 0

x-2y =0...... eq1

now reversed number is 10y + x

so, 10y+x = 10x+y-18

-9x +9y = -18

x-y = 2....... eq2

eq1 - eq2

y= 2

x = 4

so number is 42

Answer 2

Answer:

let's two digits number be 10x+y

give, the number is 7 time

the sum of it's digits

10x+y =y7 (x+y)

10×+y=7x+7y

3x=6y

x=2

10x+y -10y-x=18

9x-9y=18

9x(x-y)=18

(x-y)=18

(x-y) =18/9=2

x-y=2

x=2y

2y=y=2

y=2

x=4

the number is 42