Encuentra el valor de la variable . o incógnita en las siguientes ecuaciones. .a. y+13=46​

Can someone explain the elimination method to me for this problem?

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.

Find two consexutive odd integers such that the sum of their square is 650