What we've done here, basically, is omitted 2 of the notes from each of the original Melodic Minor scales (D Melodic Minor, omit G & C#, and Bb Meodic Minor, omit Bb & Eb), thereby creating 2 altered pentatonics.
For the D min tonic chord, we'll use a D pentatonic b3 (D-E-F-A-B), which has a more "obvoius" tonic sound than our other MM choice, the pentatonic b6, which is what we'll use for the A7alt dominant chord (F pentatonic b6 = Bb Melodic Minor = F-G-A-C-Db). The D min pentatonic supplies us with a good old Dmin6 9 sound, while the fore mentioned F pentatonic b6 gives us an A7 #9b13, and includes the tritone C#(Db) & G.
As in the previous exercise, both scales are played alternately in a single direction, each measure beginning on the next available scale tone.
Note: Measure 4 of Line 4 should be labeled as an A7alt chord.