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31 votes
31 votes
7. How many solutions does this system of equations have? Explain howyou know. *y=-42 +32x + 8y = 10

7. How many solutions does this system of equations have? Explain howyou know. *y-example-1
User KNfLrPn
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1 Answer

19 votes
19 votes

Given:


\begin{gathered} y=-4x+3------1 \\ 2x+8y=10-----2 \end{gathered}

Substitute y = -4x + 3 into equation 2

This gives


2x+8(-4x+3)=10

Simplify and solve for x


\begin{gathered} 2x-32x+24=10 \\ -30x=10-24 \\ -30x=-14 \\ x=(-14)/(-30) \\ x=(7)/(15) \end{gathered}

Substitute x = 7/15 into equation 1

This gives


y=-4((7)/(15))+3

Solve for y


\begin{gathered} y=-(28)/(15)+3 \\ y=(-28+45)/(15) \\ y=(17)/(15) \end{gathered}

Therefore, there are two solution


x=(7)/(15),y=(17)/(15)

User Kristoffer Berge
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