# How do you solve the following linear system -4x +9y = 5 , x - 4y = -3 ?

Jun 15, 2016

x=1; y=1

#### Explanation:

First, let's obtain x in the second equation:
$x = 4 y - 3$

then let's substitute its value in the first one:
$- 4 \left(4 y - 3\right) + 9 y = 5$

then, by simplifying:
$- 16 y + 12 + 9 y = 5$
$- 16 y + 9 y = - 12 + 5$
$- 7 y = - 7$
$y = 1$

and now let's substitute the value of y in
$x = 4 y - 3$

so that
$x = 4 \cdot 1 - 3$
$x = 1$
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