SOLUTION: Please help me solve for Y 1) 2xy + 1 = xy + 3 2) 3/4x + 4/7y = 5/4x - 1 3)3/5y-4x = 3-2y

Algebra ->  College  -> Linear Algebra -> SOLUTION: Please help me solve for Y 1) 2xy + 1 = xy + 3 2) 3/4x + 4/7y = 5/4x - 1 3)3/5y-4x = 3-2y      Log On


   

Question 156676: Please help me solve for Y
1) 2xy + 1 = xy + 3
2) 3/4x + 4/7y = 5/4x - 1
3)3/5y-4x = 3-2y
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'll do the first two to get you started

# 1

2xy+%2B+1+=+xy+%2B+3 Start with the given equation


2xy+%2B+1+-+xy+=+3 Subtract xy from both sides


2xy+-+xy+=+2 Subtract 1 from both sides


xy+=+2 Combine like terms.


y=2%2Fx Divide both sides by x to solve for y

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Answer:

So the solution is y=2%2Fx



# 2




%283%2F4%29x%2B%284%2F7%29y=%285%2F4%29x-1 Start with the given equation.


28%28%283%2Fcross%284%29%29x%2B%284%2Fcross%287%29%29y%29=28%28%285%2Fcross%284%29%29x-1%29 Multiply both sides by the LCD 28 to clear any fractions.


21x%2B16y=35x-28 Distribute and multiply.


16y=35x-28-21x Subtract 21x from both sides.


16y=14x-28 Combine like terms on the right side.


y=%2814x-28%29%2F%2816%29 Divide both sides by 16 to isolate y.


y=%2814x%29%2F%2816%29-%2828%29%2F%2816%29 Break up the fraction


y=%287%2F8%29x-7%2F4 Reduce

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Answer:

So the solution is y=%287%2F8%29x-7%2F4