Solve the following for X and Y: 2y+4x=14 and x-y=-1
Firstly, Take equation 1 (2y+4x=14) and divide it all by 2. This gives y+2x=7. Next make Y the 'subject' AKA put it on it's own. To do this Subtract 2x from both sides. Now we have Y=7-2X. Here you can see Y and 7-2x are exactly the same (hence the = sign).
Now get equation 2 and substitute in the 7-2x for Y since they are the same. so x-y=-1 goes to x-(7-2x)=-1. Expanding this gives x-7+2x=-1 which gives 3x-7=-1. Add 7 to both sides 3x=6 so x=2. Sub x=2 into x-y=-1.... 2-y=-1. Add y to both sides and add one to both sides. y=3.
Final answer is Y=3 and x=2
TM
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