Respuesta :

This week the number of lawns "times" 25 and his allowance = $345

Therefore...

25x + 20 = 345

      - 20     -20

25x         = 325

Now divide both sides by the coefficient (25)... and that will be the number of lawns he mowed.

Hope this helps!

345-20(allowance)= 325
Now you divide 325 by amount of earned from mowing lawns which gives you 13
(325/25)=13