Question

The sum of a two digit number is 8.the number obtained by interchanging two digit number exeed the given number by 18.find the number

Answer 1

Let the no. be 10x+y
x at tens place and y at unit place
x+y=8
Interchanging the digit we get 10y +x

ACC.to equation

10x+y-(10y+x)=18
After solving

we get
10(x-y)+(y-x)=18
10(x-y)-1(x-y)=18
(x-y)(10-1)=18
9(x-y)=18
x-y=2

now solving these equations we get x=5 and y=3
so the no. is 53

Answer 2

Hey there ‼
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Let the two digit number be 10y + x.
Given that, x + y = 8 ...(1)

Number obtain after inter-changing two digits = 10x + y

A.T.Q.
10x + y = 10y + x + 18
10x – x – 10y + x = 18
9x – 9y = 18
x – y = 2 ...(2)

Subtracting (1) and (2)

x + y = 8
x – y = 2
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0 +2y = 6
y = 6 / 2
y = 3

Substituting y = 3 in (1)
x + 3 = 8
x = 8 – 3
x = 5

Thus, the two digit number is 10y + x i.e., 10(3) + 5 = 30 + 5 = 35
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Hope my ans.'s satisfactory..‼ (^-^)