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How many solutions does the system have X+ 4Y= 6 Y= 2X -3

User EducateYourself
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1 Answer

16 votes
16 votes

To solve this system, let's apply the value of y from the second equation in the first one:


\begin{gathered} \begin{cases}x+4y=6 \\ y=2x-3\end{cases} \\ \\ x+4\cdot(2x-3)=6 \\ x+8x-12=6 \\ 9x=6+12 \\ 9x=18 \\ x=2 \\ \\ y=2\cdot2-3 \\ y=4-3=1 \end{gathered}

So this system has just one solution, which is (2, 1).

User Dao
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