How do you solve the following system?: $- x + 5 y = 7, x = - 2 y + 1$ $-x+5y=7 , x=-2y+1$

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How do you solve the following system?: $- x + 5 y = 7, x = - 2 y + 1$ $-x+5y=7 , x=-2y+1$

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Answer 1 · 2015-11-14T15:15:59

Use linear combination or substitution.

Explanation:

Add the two equations together.
$- x + 5 y = 7$ $-x+5y=7$
$+ (x + 2 y = 1)$ $+(x+2y=1)$
$0 x + 7 y = 8$ $color(red)(0x+7y=8)$
Therefore, $7 y = 8$ $7y=8$ and $y = \frac{8}{7}$ $y=8/7$ . From here, plug $\frac{8}{7}$ $8/7$ in for $y$ $y$ in either equation and solve for $x$ $x$ .

Another option would be substitution, since from the second equation you know that $x = - 2 y + 1$ $x=-2y+1$ , would be to replace $x$ $x$ with $- 2 y + 1$ $-2y+1$ in the equation $- x + 5 y = 7$ $-x+5y=7$ .

This would give: $- (- 2 y + 1) + 5 y = 7$ $-(-2y+1)+5y=7$
$2 y - 1 + 5 y = 7$ $2y-1+5y=7$
$7 y - 1 + 7$ $7y-1+7$
$7 y = 8$ $7y=8$
Again, we see that $y = \frac{8}{7}$ $color(blue)(y=8/7)$ and we would use that value to determine that $x = - \frac{9}{7}$ $color(blue)(x=-9/7)$ .

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How do you solve the following system?: $- x + 5 y = 7, x = - 2 y + 1$ $-x+5y=7 , x=-2y+1$

1 Answer

Explanation:

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Science

Math

Humanities

... and beyond

How do you solve the following system?: −x+5y=7,x=−2y+1 -x+5y=7 , x=-2y+1

1 Answer

Explanation:

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Impact of this question

How do you solve the following system?: $- x + 5 y = 7, x = - 2 y + 1$ $-x+5y=7 , x=-2y+1$