Pls helpop

Tim open up a new saving account with a $50 deposit and plant to deposit $20 per week into the same account.write an expression to represent the total amount in his savings account.

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

50 points and will mark brainlest if you were constructing a triangular frame, and you had wood in the length of 4inches, 4 inches, and 7 inches, would it make a triangle? would you be able to create a frame from these pieces of wood? yes or no? = explain your mathematical thinking: