Answer:
Let the Dulcina's collection be 'x'
Let the Tremaine collection be 'x-39'
x + x - 39 =129
2x = 129 +39
2x = 168
x = 168/2
x = 84
Dulcina's collection = x = 84
Tremaine's collection = x - 39 = 84 - 39 = 45
Answer:

Step-by-step explanation:
Answer:
10
Step-by-step explanation:
712.9 / 10 = 71.29
Answer:
4x-10
Step-by-step explanation:
Multiply both by 2, 2x times 2 is 4x, and 5 times 2 is 10, so it becomes 4x-10.