Exercises

1.
 The sum of both numbers of a number is 14. On having exchanged the numbers of the tens with that of the units, the number increases in 18. It finds the original number.

2.
 The sum of two numbers is 21 and his difference is 5. ¿Which are the numbers?

Please I am grateful for them to him very much indeed ...:)



Answer :

Ryan2
a)
Note that there are only two numbers that correspond complete wording of question: 59 and 68
It is easy to verify that the number found number is 68:

Look:
6 + 8 = 14 and
86 - 68 = 18

b)
Now you can solve one system:

x + y = 21
x - y = 5

Add both equations:

2x = 26
x = 13

So: y = 8