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

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Answer 1 · 2018-07-30T13:42:17

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

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

$x + 7 = 4$

$x = 4 - 7 = -3$

Substituting the value of x in Eqn (1),

$-2 * -3 + 9y = 15$

$6 + 9y = 15$

$9y = 15 - 6 = 9$

$y = 1$

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

Answer 2 · 2018-07-30T20:49:24

$(-3,1)$

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

$-2(-3)+9y=15$

$9y+6=15$

$9y=9=>y=1$

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

Hope this helps!

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