Hi I was doing these textbook problems for physics and I was having trouble doing them. I was trying to learn ahead and was a bit confused hopefully some help

(1) The drawing shows six point charges arranged in a rectangle. 47 +3q +59 The value of q is 9.0 /C, and the distance d is 0.13 m. Find d d the total electric potential at location P, which is at the center of the rectangle. d d d 5q -3q +7q (2) Two identical point charges (q =+7.20 x 10-6 C) are fixed at diagonally opposite comers of a square with sides of length 0.480 m. A test charge (q0 --2.40 x 10-8 C), with a mass of 6.60 x 10-8 kg, is released from rest at one of the empty corners of the square. Determine the speed of the test charge when it reaches the center of the square