How do I solve a question like this? Im confused

What is the area of triangle pqr on the grid? a triangle pqr is shown on a grid. the vertex p is on ordered pair 7 and 6, vertex q is on ordered pair 1 and 6, and the vertex r is on ordered pair 4 and 2. 5 square units 6 square units 10 square units 12 square units

Find the balance at the end of 4 years if 1000 is deposited at the rate of

What are “like terms”? why can we only add like terms?