3 years ago

X and y is the variable 4x-7y=3 x-7y=-15 what is the answer please

1 answer:

6 0

Use linear combination to solve this. It is much faster than substitution. I would start by multiplying the bottom equation by -1.
<span>4x-7y=3
-x+7y=15</span>
Then, add the two equations together. The result is:
3x=18.
You've eliminated one variable. Now you can solve for the other one.
Divide both sides by 3 to get
x=6
Plug this into one of the original equations, then solve for y
-(6)+7y=15
7y=21
y=3

Check your work by plugging these values into both equations to see if they remain true

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