Please provide the solution to the following math problems and the answer to the history question.

Math Problem 1

• Given equation: (8x - 1)/2 = -5 - (4 - 3x)
• Step 1: Multiply both sides by 2 to eliminate the fraction: 8x - 1 = -10 - 2(4 - 3x)
• Step 2: Distribute the -2 on the right side: 8x - 1 = -10 - 8 + 6x
• Step 3: Combine like terms on the right side: 8x - 1 = -18 + 6x
• Step 4: Subtract 6x from both sides: 2x - 1 = -18
• Step 5: Add 1 to both sides: 2x = -17
• Step 6: Divide by 2: x = -17/2

Math Problem 2

• Given equation: 6x - 22 - 20 + 15x = 0
• Step 1: Combine like terms: 21x - 42 = 0
• Step 2: Add 42 to both sides: 21x = 42
• Step 3: Divide by 21: x = 2

History Question

The question is: "Why is the unification of lands around Moscow called the 'gathering of lands' and what is its significance for Russia?"

Brief explanation: This historical period is termed the "gathering of lands" because it describes the process by which the Grand Principality of Moscow consolidated various Russian principalities under its rule, often through a combination of military conquest, diplomacy, and economic influence. This consolidation was crucial for the formation of a centralized Russian state, laying the foundation for its future territorial expansion and political power.