Answer:
The solution is x = -2, y = -3
Step-by-step explanation:
Let's start with the equation 3x + y = -9
Substitute the y for 5x+7 seen in the second equation
Now you have 3x + (5x+7) = -9
Lets solve:
Let's add the x's
Now we have 8x + 7 = -9
Substracy seven from each side
Now we have 8x = -16
Now let's divide 8 on each side
Now we have x = -2
Now lets plug in -2 to the second equation
The second equation is y = 5x+7
When we plug in -2 we get y=5(-2)+7
We multiply
We now have y = -10+7
Add
y = -3
The solution is x = -2, y = -3
Answer: 
Step-by-step explanation:
The equation of the line is Slope-intercept form is:

Where "m" is the slope and "b" the y-intercept.
The slopes of perpendicular lines are negative reciprocal.
Then, if the slope of the first line is -3, the slope of the other line must be:

Substitute the point (3,4) into the equation and solve for b:

Then the equation of this line is:

Answer:-10
Step-by-step explanation:
45 +5=-5x
-5x=50
X=-10
whats the shape or whatever it is