number riddle, algebra help please!?

[Swaym~]

The sum of the digits of a two-digit number is 7. When the digits are reversed, the number is increased by 27. Find the number please

 

[henry_yang67]

xy is the number
x+y = 7
y*10+x = x*10+y + 27
9y = 9x + 27
y = x+3
x = 4
y = 7
the number is 47
reversed number is 74 = 47 + 27

 

[JunAgruda]

Tens (x), unit :
x + y = 7
y = 7 - x

10y + x - (10x + y) = 27
10y + x - 10x - y = 27
9y - 9x = 27
y - x = 3
y = x + 3

7 - x = x + 3
2x = 4
x = 2

y = 7 - 2
y = 5

Answer: 25 (many solutions as Henry's 47 also apply).

 

[RYaesqe]

Ok, so lets work this out:
what 2 digits equal 7?

- 5+2
- 3+4 (lets try this one)

Now you must reverse the digits, so:
3+4=7
34 - 7 = 27

Your riddle #'s are: 4 & 3.

Good luck.

 

[wirehawkboston]

4 + 3 = 7

34 - 7 = 27

Numbers are 4 and 3.