Please solve this problem, include step-by-step solutions please. Thanks!

1. An equilateral triangle has sides of 0.15 m. A -9.0 pC charge is located at the top corner, a +8.0 [10 is positioned at the lower left corner, and a +2.0 [10 is placed at the lower right corner of the triangle. Find the magnitude of the net electrostatic force on the +2.0 [10 charge. 2. Point charges of 2 x109 C are situated at each of the three corners of a square whose side is 0.2 m. What would be the magnitude and direction of the resultant force on a point charge of -1 x 10'19 C if it was placed at the lower left corner of the square