# How do you solve 3x+3y=15 and 2x+3y=-5?

Aug 3, 2015

The solution for the system of equations is
color(blue)(x=20,y=-15

#### Explanation:

$3 x + \textcolor{b l u e}{3 y} = 15$.....equation $\left(1\right)$

2x+color(blue)(3y)=−5....equation $\left(2\right)$

Solving by elimination
Subtracting equation $2$ form $1$ results in elimination of color(blue)(3y:

$3 x + \cancel{\textcolor{b l u e}{3 y}} = 15$

$- 2 x - \cancel{\textcolor{b l u e}{3 y}} = + 5$

x=color(blue)(20

Substituting $x$ in equation $1$ to find $y$
$3 y = 15 - 3 x$
$3 y = 15 - 3 \cdot \left(20\right)$

$3 y = 15 - 60$

$y = - \frac{45}{3}$

color(blue)(y=-15