Let [tex]x[/tex] be the larger number and [tex]y[/tex] the smaller number.
The first sentence translates to [tex]x=8+3y[/tex]. The second translates to [tex]x+y=52[/tex].
Since [tex]x=8+3y[/tex], you can substitute this into the second equation to get
[tex](8+3y)+y=4y+8=52\implies 4y=44\implies y=11[/tex]
Then substituting this into the original second equation gives
[tex]x+11=52\implies x=41[/tex]
