Answer:  y = -(9/5)x - 1
Step-by-step explanation:
Rewrite the equation in standard form:  y = (5/9)x+(8/9).  [y=mx+b]
A line perpendicular to this would have a slope that is the negative inverse of the original slope (5/9), which would make it -(9/5).  The y-intercept would also change, but we don't know the value, yet.  For now, we'll use "b" for the y-intercept.  This results in a perpendicular line:
y = -(9/5)x + b
We can calculate b, the y-intercept, by using the point (-5,8) and solving for b.
8 = -(9/5)*(-5) + b
8 = (9) + b
b = -1
The line perpendicular to 5x−9y=−8 that passes through the point (−5,8) is
y = -(9/5)x - 1
 
        
             
        
        
        
Answer:
y = (1/4)x
Step-by-step explanation:
"Direct variation" here signifies y = kx, where k is the constant of proportionality.
Then y = kx.  Here we are to find k using the info that x = 12 and y = 3:
3 = k(12), or
k = 3/12, or k = 1/4
Then y = (1/4)x
 
        
                    
             
        
        
        
Answer:
x = 0, y = 7
Step-by-step explanation:
Solving a system of equations using substitution requires one side to be equal to a variable present in the equation, in this case x or y. We should simplify the equation using elimination before substituting to reduce the chance of error.
In order to use the elimination method, you have to create variables that have the same coefficient—then you can eliminate them. These equations arew already aligned for us.
                   3x - 10y=-70
              -<u>   4x +9y = 63</u>
                   -x + y = 7
Now, for substitution, the equation must be set to a variable.
                   -x + y = 7
                   y = x + 7
Next, plug the equation in where applicable in another equation.
                   4x +9(x + 7) = 63
                   4x + 9x + 63 = 63
                   13x = 0
                   x = 0
The final step of substitution is to plug the known variable into an equation to find the other variable.
                   3(0) - 10y=-70
                   0 - 10y = -70
                   10y = 70
                   y = 7
I guarantee you this answer is correct, I worked it out using other methods and graphing prior to submitting this answer.