Answer:
[tex]\large \boxed{\text{868 and 966 km/h}}[/tex]
Step-by-step explanation:
Let x = the speed of plane A
Then 98 + x = the speed of Plane B
and 98 + 2x = the speed at which the planes are separating
and 2(98 + 2x) = their separation after 2 h
[tex]\begin{array}{rcl}2(98 + 2x) & = & 3668\\98 + 2x & = & 1834\\2x & = & 1736\\x & = & \mathbf{868}\\98+ x& = &98 + 868\\& = & \mathbf{966}\\\end{array}\\\text{The speeds of the two planes are $\large \boxed{\textbf{868 and 966 km/h}}$}[/tex]
Check:
[tex]\begin{array}{rcl}2[98 + 2(868)]& = & 3668\\\\2(98 + 1736) & = & 3668\\\\2(1834) & = & 3668\\3688 & = & 3668\\\end{array}[/tex]
OK