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X/2+y=4/5. x+y/2=7/10

User Ttom
by
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2 Answers

3 votes

The answer is x = 2/5, y = 3/5 or (2/5, 3/5)

First, in order to avoid fractional values during calculation, multiply both equations by 10 to simplify.

  1. 10 (x/2 + y) = 10 (4/5) ⇒ 5x + 10y = 8
  2. 10 (x + y/2) = 10 (7/10) ⇒ 10x + 5y = 7

Multiply the 1st equation by 10 and 2nd equation by 5.

3. 10 (5x + 10y) = 10 (8) ⇒ 50x + 100y = 80

4. 5 (10x + 5y) = 5 (7) ⇒ 50x + 25y = 35

Subtract : 3rd equation - 4th equation

  • 50x + 100y - 50x - 25y = 80 - 35
  • 75y = 45
  • y = 3/5

Now, substitute for x in the 1st equation to find y.

  • x/2 + 3/5 = 4/5
  • x/2 = 1/5
  • x = 2/5
User Lien
by
3.3k points
3 votes

Answer:

x = 2/5

y = 3/5

Explanation:

**Disclaimer** Hi there! I assumed the question to be a system of equations. The following answer is a method for solving a system of equations. Thus, if it is not, please let me know and I will modify my answer.

Given information:


(x)/(2)+y=(4)/(5)


x+(y)/(2) =(7)/(10)

Eliminate fractions by multiplying 10 on both sides of the first equation:


10*(x)/(2)+10*y=10*(4)/(5)


5x+10y=8

Eliminate fractions by multiplying 10 on both sides of the second equation:


10*x+10*(y)/(2) =10*(7)/(10)


10x+5y=7

Current system:


5x+10y=8


10x+5y=7

Multiply the second equation by 2:


5x+10y=8


20x+10y=14

Subtract the first equation from the second equation:


(20x+10y)-(5x+10y)=14-8


20x+10y-5x-10y=6


(10y-10y)+20x-5x=6


0+15x=6


\boxed{x=(2)/(5) }

Substitute the x value back to one of the equations to get the y value:


x+(y)/(2) =(7)/(10)


((2)/(5)) +(y)/(2) =(7)/(10)


((2)/(5)) +(y)/(2)-(2)/(5) =(7)/(10)-(2)/(5)


(y)/(2) =(3)/(10)


(y)/(2)*2 =(3)/(10)*2


\boxed{y=(3)/(5) }

Hope this helps!! :)

Please let me know if you have any questions

User Steve Wash
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2.9k points