# How do you solve the system 7 + 2y = 8x and 3x - 2y = 0 by substitution?

Jun 22, 2018

$x = \frac{7}{5} , y = \frac{21}{10}$

#### Explanation:

from the second equation we get

$x = \frac{2}{3} y$
plugging this in the first one:

$7 + 2 y = \frac{16}{3} y$
$7 = \frac{16}{3} y - 2 y$
$7 = \frac{10}{3} y$
so $y = \frac{21}{10}$
$x = \frac{7}{5}$