Question

in a two digits number some of the two digits is 7 if 19 is added to the number the digits are reversed.find the number​

Answer 1

Step-by-step explanation:

Hey guys how are you hope that you will be fine my best wishes are with you stay happy, healthy and wealthy

stay home stay safe

thankyou☺

Answer 2

correct question :-

in a two digits number sum of the two digits is 7 . if 18 is added to the number the digits are reversed . find the number .

we have :-

• sum of two digits number is 7.
• if we added added 18 to the number te digits are reversed.

To find :-

• the two digits number .

solution :-

• let unti digit number = x
• tens digit number = y

ATQ

x + y = 7 ............eq.(1)

when 18 is added to the number , number reversed :-

10x + y + 18 = 10y + x

10x – x + y – 10y + 18 = 0

9x – 9y + 18 = 0

divided by 9 we get :-

x – y + 2 = 0

x – y = –2 .............eq.(2)

add eq.(1) and (2) we get :-

x + y = 7

x – y = – 2

2x = 5

x = 5/2

put the value of x = 5/2 in eq (1) we get :-

$\sf \: x + y = 7 \\ \\ \sf \implies \: \: \dfrac{5}{2} + y = 7 \\ \\ \sf \implies \: \: y = 7 - \dfrac{5}{2} \\ \\ \sf \implies \: \: y = \dfrac{14 - 5}{2} \\ \\ \sf \implies \: \: y = \dfrac{9}{2}$

hence,

$\bf \blue\bigstar \: \: x = \dfrac{5}{2} \\ \\ \bf \blue\bigstar \: \:y = \dfrac{9}{2}$