# How do you solve the system of equations -2x + 9y = 15 and x + 7= 4?

Jul 30, 2018

color(blue)(x = -3, y = 1

#### Explanation:

$- 2 x + 9 y = 15$, Eqn (1)

$x + 7 = 4$

$x = 4 - 7 = - 3$

Substituting the value of x in Eqn (1),

$- 2 \cdot - 3 + 9 y = 15$

$6 + 9 y = 15$

$9 y = 15 - 6 = 9$

$y = 1$

Thus, our solutions are $x = - 3$ and $y = 1$.

Jul 30, 2018

$\left(- 3 , 1\right)$

#### Explanation:

In the second equation, we can easily solve for $x$ in the second equation by subtracting $7$ from both sides. We get

$x = - 3$

Now, we can plug this into the first equation to solve for $y$. We get

$- 2 \left(- 3\right) + 9 y = 15$

$9 y + 6 = 15$

$9 y = 9 \implies y = 1$

Therefore, our solution is at the point $\left(- 3 , 1\right)$

Hope this helps!