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# simultaneous equations

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simultaneous equations

5x+2y=-2

3x-5y=17.4

yahya  May 13, 2017

#1
+7089
+4

For this we can use the elimination method.

5x + 2y = -2

3x – 5y = 17.4

Multiply the top equation through by $$\frac52$$ .

$$\frac{25}{2}$$ – 5y = -2

Now line this up with the second equation and add straight down.

$$\frac{25}{2}$$x    +    5y = -5

+   3x      –    5y = 17.4

15.5x +    0y = 12.4

15.5x = 12.4

x = 12.4/15.5

x = 0.8

Now just use this value for x in either equation to find y.

5(0.8) + 2y = -2

4 + 2y = -2

2y = -6

y = -3

hectictar  May 13, 2017
#1
+7089
+4

For this we can use the elimination method.

5x + 2y = -2

3x – 5y = 17.4

Multiply the top equation through by $$\frac52$$ .

$$\frac{25}{2}$$ – 5y = -2

Now line this up with the second equation and add straight down.

$$\frac{25}{2}$$x    +    5y = -5

+   3x      –    5y = 17.4

15.5x +    0y = 12.4

15.5x = 12.4

x = 12.4/15.5

x = 0.8

Now just use this value for x in either equation to find y.

5(0.8) + 2y = -2

4 + 2y = -2

2y = -6

y = -3

hectictar  May 13, 2017