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Solve the simultaneous equations
5x-4y=19
x+2y=8

User Krisna
by
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2 Answers

5 votes
the answer are x= 5 and y = 3/2
Solve the simultaneous equations 5x-4y=19 x+2y=8-example-1
User Msharp
by
8.2k points
1 vote
So to solve for x and y you need to add the two equations together, and to do this when you add them either the x or the y need to cross out.

For this equation we’re going to multiply the bottom equation by 2 so that the y’s will cancel out when we ad the equations together so that we can solve for x

5x-4y=19
2(x+2y=8)

Distribute the 2

5x-4y=19
2x+4y=16

Next add the two equations together

7x=35

As you can see the y was cancelled out. Now divide each side by 7 to solve for x

x=5

Now take this answer and plug it back into either equation to solve for y. I am going to plug it into the second equation, but you can choose either

x+2y=8

Replace x with its value, 5

5+2y=8

Subtract 5 from each side

2y=3

Divide each side by 2

y=3/2 (or 1.5)

ANSWER:

x = 5

y = 3/2 (or 1.5)

User Papanito
by
7.5k points

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