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2 votes
7x+3y=22 4y=20 I need to know how to write this equation out with the answer

User Tura
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2 Answers

4 votes
7x+3y=22
4y=20

4y=20
y=5

Substitute to first equation
7x+15=22
7x=7
x=1
User Gohu
by
7.4k points
2 votes

\begin{cases} 7x+3y=22 \\ 4y=20 \ \ /:4 \end{cases}\\ \\\begin{cases} 7x+3 \cdot 5=22 \\ y= 5 \end{cases}\\ \\\begin{cases} 7x+15=22 \ \ |-15 \\ 4y=20 \end{cases}


\begin{cases} 7x+15 -15=22 -15 \\ y=5 \end{cases}\\ \\\begin{cases} 7x =7\ \ / :7 \\ y=5 \end{cases}\\ \\\begin{cases} x =1 \\ y=5 \end{cases}\\ \\


User Ron Norris
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