Question 462558


let's numbers be {{{x}}} and {{{y}}}

given:

The sum of two numbers is 55:

 {{{x+y=55}}}...........1

 and the difference is 15:


 {{{x-y=15}}}...........2

solve this system:

{{{x+y=55}}}...........1

 {{{x-y=15}}}...........2
------------------------------add them

{{{x+x+y-y=55+(-15)}}}

{{{2x+cross(y)-cross(y)=40}}}

{{{2x=40}}}

{{{x=40/2}}}

{{{x=20}}}

now find {{{y}}}


{{{x+y=55}}}...........1

{{{y=55-x}}}

{{{y=55-20}}}

{{{y=35}}}

so, your numbers are  {{{20}}} and {{{35}}}