Answer:
V1 = 700 cos 69.8 i + 700 sin 69.8 j vector components of V1
V1 = 241.7 i + 656.9 j in miles/hour
V2 = 620 cos 107 i + 620 sin 107 j
V2 = -181.3 i + 592.9 j
V = V1 - V2 = 423 i + 64 j rate of planes separation
1.9 V = 803.7 i + 121.6 j miles separation of planes after 1.9 hr
D = (803.7^2 + 121.6^2)^1/2 = 812.8 miles