How do I Solve this by substitution?
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[tex]If\ y=x+3\ and\ y=2x+4,\ then\\\\x+3=2x+4\qquad\text{subtract 3 from both sides}\\\\x=2x+1\qquad\text{subtract 2x from both sides}\\\\-x=1\qquad\text{change the signs}\\\\x=-1\\\\\text{put the value of x to the first equation}\\\\y=-1+3=2\\\\Answer:\ \boxed{x=-1,\ y=2\to(-1,\ 2)}[/tex]