# How do you solve 7x-y=44 and x+4y=27 by elimination?

Feb 14, 2017

Not sure what you mean by "elimination" but I do it this way.....

#### Explanation:

First, $7 x - y = 44$ therefore $7 x = 44 + y$ and $x = \frac{44 + y}{7}$
Also, $x + 4 y = 27$ therefore $x = 27 - 4 y$

Therefore $44 + y = 7. \left(27 - 4 y\right)$
And therefore $44 + y = 189 - 28 y$ by multiplying out the bracket.
So $y + 28 y = 189 - 44$
And $29 y = 145$
Therefore $y = \frac{145}{29} = 5$.

And we already know that $x = 27 - 4 y$
So substituting in y we get $x = 27 - \left(4.5\right) = 27 - 20 = 7$.