Please help, with math homework

X+ y = 5 ; x - y =3 solve using linear combination

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236

Maddie's rectangular kitchen has an area of 10 square yards and a length of 3 3/4 yards.how many yards wide is maddie's kitchen?