Question

a number consists of two digits whose sum is 7 if 45 is added to the number the digits are reversed find the number​

Answer 1

Answer:

Let the no. be x and y

Step-by-step explanation:

A.T.Q

x+y=7--------------------1

10x+y=10y+x+45

-9x+9y=45

-x+y=5---------------------2

ADD 1 and 2

2y=12

y=6

Put In 1

x=6+x=7

x=1

MARK AS BRAINLIEST

Answer 2

Answer:

let  one digit be x and other be y.

x+y=7

x=7-y          ---------------------(i)

let x>y

so, let x be at unit's place .

then y will at ten's place.

THEN ORIGINAL NUMBER =10(y)+x

ON INTERCHANGED DIGITS:-

WE WILL GET:-

NUMBER =10(x)+y

ORIGINAL NUMBER +45 = INTERCHANGED NUMBER.

∴ 10y+x+45=10x+y

∴ 10y-y+45=10x-x

∴ 9y +45=9x

∴ 9(y+5) =9(x)

∴ y+5=x

SUBSTITUTE VALUE OF x from (i) :-

∴ y+5=7-y

∴ y+y=7-5

∴ 2y =2

∴ y=2/2

∴ y=1

ORIGINAL NUMBER =10y+6

=10(1)+6

=16

INTERCHANGED NUMBER =61