Two forces F1 and F2 act on a particle, where F1 = (5i + 2j) N and F2 = (-3i + 4j) N. (a) Find the resultant force R = F1 + F2. (b) Find the magnitude of R and the angle it makes with the positive x-axis, correct to one decimal place. (c) A third force F3 is applied to the particle so that the particle remains in equilibrium. Find F3. (d) Given that a = (2i - j) and b = (i + 3j), find the values of scalars p and q such that pa + qb = F1.