The correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
The given system of equations is;
The first step would be to rearrange the variables in the second equation so we have a defined expression for x.
We would want to do this so we could then plug in the defined expression for x into the other equation and solve for the other variable.
x + 4y = 19
Rearrange this by getting the 4y to the other side.
We can get 4y on the other side by subtracting 4y from both sides
x + 4y - 4y = 19 - 4y
x = -4y + 19
Hence, the correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
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