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# Equations watch

1. 5a+y=15
2a+6y=34
How the heck do I do this
2. This is a simultaneous equation
Firstly, the way I do it is by eliminating the x first

To do this, you have to make the y values for both equations the same. In this instance, you can multiply the top one by 6 to make it 6y (same as bottom)
Note you have to multiply all values in the equation you are multiplying.

Therefore, you'd get
30a + 6y = 90
2a + 6y = 34

Theres a rule of if its the same sign, we subtract, and as we can see there are two addition signs in the equation.
So we get:
28a = 56 (bcos 30-2 = 28 and 90-34 = 56)
so a = 2

To get y we just input the a value to the first set of equations we started with.
so 5a + y = 15
5 x 2 + y = 15
10 + y = 15
y must be 5

(can check with bottom equation it is correct)
3. a is 2 and y is 5.

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Updated: May 19, 2017
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