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# how do you solve this simultaneous equation? Watch

1. 5x-19=2y
2x-y/3=2
2. (Original post by p29)
5x-19=2y
2x-y/3=2
times the second equation by 5/2 then subtract and solve
3. (Original post by 11234)
times the second equation by 5/2 then subtract and solve
how do you subtract with the fraction?
4. (Original post by p29)
how do you subtract with the fraction?
subtract second equation from first so the 5x cancels out
5. (Original post by 11234)
subtract second equation from first so the 5x cancels out
im left with -35=4y
-5y/3=10
how do i subtract these?
6. ffs
7. (Original post by p29)
im left with -35=4y
-5y/3=10
how do i subtract these?
1) 5x-19=2y
2)5x-5y/6=5

==>5y/6-19=2y-5

Finisih it off
8. (Original post by p29)
5x-19=2y
2x-y/3=2
Here are our two equations.

5x - 19 = 2y (1)
2x - y/3 = 2 (2)

Multiply equation (2) by 3 to get rid of the fraction.

5x + 2y = 19 (1)
6x - y = 6 (2)

Rearrange to get y on its own.

y = 6x - 6

Therefore, by substituting our new value for y into equation (1),

5x + 2(6x - 6) = 19

Simplify and rearrange,

5x + 12x - 12 = 19
17x = 31
x = 31/17

If x = 31/17, substitute this into equation (2) to find y.

6(31/17) - y = 6

Simplify and rearrange,

y = 6(31/17) - 6 [I don't have a calculator so you'll have to do the maths yourself]

And therein you have your two solutions.
9. (Original post by jake4198)
Here are our two equations.

5x - 19 = 2y (1)
2x - y/3 = 2 (2)

Multiply equation (2) by 3 to get rid of the fraction.

5x + 2y = 19 (1)
6x - y = 6 (2)

Rearrange to get y on its own.

y = 6x - 6

Therefore, by substituting our new value for y into equation (1),

5x + 2(6x - 6) = 19

Simplify and rearrange,

5x + 12x - 12 = 19
17x = 31
x = 31/17

If x = 31/17, substitute this into equation (2) to find y.

6(31/17) - y = 6

Simplify and rearrange,

y = 6(31/17) - 6 [I don't have a calculator so you'll have to do the maths yourself]

And therein you have your two solutions.
I got y=-12 and x=-1. Not sure your values satisfy 1
10. I made this animated PowerPoint a while back explaining techniques to solve simultaneous equations, if it helps:
https://www.dropbox.com/s/ono0irvomy...ions.pptx?dl=0
11. (Original post by 11234)
I got y=-12 and x=-1. Not sure your values satisfy 1
Do the math by using the calculated values. If you get the equal value on both sides in one of the equations, the calculated values are right.

For me the calculation steps of jake4198 look good.
12. (Original post by Kallisto)
Do the math by using the calculated values. If you get the equal value on both sides in one of the equations, the calculated values are right.

For me the calculation steps of jake4198 look good.
for jake x=31/17 y=6(31/17)-6=84/17
5(31/17)-19=-168/17 not 168/17(2x84/17)
13. (Original post by jake4198)
Here are our two equations.

5x - 19 = 2y (1)
2x - y/3 = 2 (2)

Multiply equation (2) by 3 to get rid of the fraction.

5x + 2y = 19 (1)
6x - y = 6 (2)

Rearrange to get y on its own.

y = 6x - 6

Therefore, by substituting our new value for y into equation (1),

5x + 2(6x - 6) = 19

Simplify and rearrange,

5x + 12x - 12 = 19
17x = 31
x = 31/17

If x = 31/17, substitute this into equation (2) to find y.

6(31/17) - y = 6

Simplify and rearrange,

y = 6(31/17) - 6 [I don't have a calculator so you'll have to do the maths yourself]

And therein you have your two solutions.
The emboldened steps are incorrect. It should be 5x-2y=19 and 5x - 2(6x-6)=19
14. (Original post by 11234)
for jake x=31/17 y=6(31/17)-6=84/17
5(31/17)-19=-168/17 not 168/17(2x84/17)
You said that x = -1 and y = -12 are the solutions, right? let us see, if it works in equation 5x-19 = 2y:
*
5*(-1) - 19 = 2*(-12) *
-24 = -24 *

As you can see, it works! your solutions, calculated by jake4198 are right. By the way the misplaced stars(*) are a goddamn ****ing glitch!*
15. (Original post by MartyO)
I made this animated PowerPoint a while back explaining techniques to solve simultaneous equations, if it helps:
https://www.dropbox.com/s/ono0irvomy...ions.pptx?dl=0
thank you

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