The slope is
(difference in y-values) / (difference in x-values)
= (-4) / (-5)
= 0.8
Write the equation of a line that is parallel to y=-5/4x + 7
Any line parallel to the given line will have the same slope. In an equation presented in the y-intercept form, the slope is always the coefficient of "x". In this case, the slope is -5/4 (meaning the next point is down 5, and 4 to the right).
Our equation so far looks like this: y = -5/4x + b
"b" represents the y-intercept. To solve for be, we will need to substitute values into x and y. The next piece of information it gives us is one of the points, or solutions, of the line. This means that since this point is on the line, we can use its x and y values to substitute.
x = -4
y= 1
y = -5/4x + b
1 = -5/4(-4) + b
1 = 5 + b
-4 = b
Final Answer: y = -(5/4)x -4
There are 2 roots so the only way to complete the square is,
![y=2x^2+8x-9\\y=2[(x^2+4x)]-9\\y=2[(x^2+4x+4)-4]-9\\y=2[(x+2)^2-4]-9\\y=2(x+2)^2-8-9\\y=2(x+2)^2-17](https://tex.z-dn.net/?f=y%3D2x%5E2%2B8x-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%29%5D-9%5C%5Cy%3D2%5B%28x%5E2%2B4x%2B4%29-4%5D-9%5C%5Cy%3D2%5B%28x%2B2%29%5E2-4%5D-9%5C%5Cy%3D2%28x%2B2%29%5E2-8-9%5C%5Cy%3D2%28x%2B2%29%5E2-17)
Just factor 2 out of 2x^2+8x (just ignore the -9) then find the number that will make the terms be able to complete the square.
then complete the square and multiply 2 inside the brackets.
subtraction as you already get the vertex form and know how to complete the square.
Vertex Form: 
