Someone to help me with math plis ;-;

The late fee for library books is $2.00 plus 15¢ each day for a book that is late. if maria’s fee for a late book was $3.20, write and solve a linear equation to find how many days late the book was.

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

What is the area of the triangle 10 13 12