How do you solve the system of equations $-7x + 5y = - 21$ and $- x + y = - 5$ ?

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Answer 1 · 2018-04-11T20:37:09

The solution is $x = -2$ and $y = -7$ .

I will show you how to solve this problem using the substitution method.

From the second equation we can write:

$y = x - 5$

And then we plug $y$ into the first equation:

$-7x +5*(x - 5) = -21$

$-7x + 5x -25 = -21$

$-2x = 4$

$x = -2$

At the end we solve $y = x - 5$ :

$y = -2 - 5$

$y= -7$

How do you solve the system of equations -7x + 5y = - 21-7x + 5y = - 21 and - x + y = - 5- x + y = - 5?