How do you solve 2x - 4y = 32 and 8x - 8y = 96 ?

Feb 6, 2018

Notice that we're gonna solve for $x$ first because if we solve for $x$ in the first equation... we can factorize and get $x$ without doing any kind of multiplication or something

Explanation:

We're gonna solve for $x$ first

First equation
$2 x - 4 y = 32$
$2 x = 32 + 4 y$
$x = \frac{32 + 4 y}{2}$
$x = \frac{32}{2} + \frac{4 y}{2}$
$x = 16 + 2 y$

Second equation
$8 x - 8 y = 96$
Factorize
$8 \left(x - y\right) = 96$
Transfer the 8 and put value of $x$
$16 + 2 y - y = \frac{96}{8}$
$16 + y = 12$
$y = 12 - 16$
$\textcolor{red}{y = - 4}$
Get the value of $x$
$x = 16 + 2 y$
$x = 16 + 2 \times - 4$
$x = 16 + \left(- 8\right)$
$\textcolor{red}{x = 8}$