Answer:
1) 102/21
2) 21/51
3) 21/24
Step-by-step explanation:
20 it the least common multiple of the numbers given
Answer: Need to clarify more about the question, I dont understand. Sorry ;//
Step-by-step explanation:

Substitute x = 3 in any given equations. I will do in y = - x + 1

Therefore the answer is (3,-2)
Answer:
y = 3x
Step-by-step explanation:
Given
9x - y = - 6x + 4y ( subtract 4y from both sides )
9x - 5y = - 6x ( subtract 9x from both sides )
- 5y = - 15x ( divide both sides by - 5 )
y = 3x