Question

when the unit and tens digit of a certain two digit number are reversed the sum of original number and the number so formed is 121 and their differences is 9 . What is the tens digit of original number​

Answer 1

Step-by-step explanation:

let the tens digit no. be x

let the ones digit no. be y

so the original no. =10x+y

no. formed after reversing the digits =10y+x

ATQ-

(10x+y) +(10y+x) =121

11x+11y=121

x+y=11-------(1)

(10x+y)-(10y+x) =9

(10x+y) -(10y-x) =9

9x-9y=9

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

subtracting (1) and (2), we get

x+y=11

x-y=1

----------

2x=12

x=6

x+y=11

6+y=11

y=5

the tens digit no. is 6

and the no.=10(6)+5=65

Answer 2

Concept:

First order equations include linear equations. In the coordinate system, the linear equations are defined for lines. A linear equation in one variable is one in which there is a homogeneous variable of degree 1 (i.e., only one variable). Multiple variables may be present in a linear equation. Linear equations in two variables, for example, are used when a linear equation contains two variables. Examples of linear equations include 2x - 3 = 0, 2y = 8, m + 1 = 0, x/2 = 3, and 3x - y + z = 3.

Given:

When the unit and tens digit of a certain two digit number are reversed the sum of original number and the number so formed is 121 and their differences is 9 . What is the tens digit of original number​

Find:

What is the tens digit of original number​

Solution:

let the tens digit no. be x

let the ones digit no. be y

so the original no. =10x+y

no. formed after reversing the digits =10y+x

ATQ-

(10x+y) +(10y+x) =121

11x+11y=121

x+y=11-------(1)

(10x+y)-(10y+x) =9

(10x+y) -(10y-x) =9

9x-9y=9

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

subtracting (1) and (2), we get

x+y=11

x-y=1

----------

2x=12

x=6

x+y=11

6+y=11

y=5

the tens digit no. is 6

and the no.=10(6)+5=65

Therefore,the number is 65

#SPJ2