Answer:
1. line a and c and parallel. line b is perpendicular with line a and c. 2. line b and c and parallel. line a is perpendicular to lines b and c. 3. y= -3x + 3 4. y=(5/3)x - 9
Step-by-step explanation:
To find parallel and perpendicular, make the slope opposite and find b by plugging in the points. Parallel is the same slope.
You just need to plug those expressions inside the formula: it doesn't matter if they're expressions involving a variable instead of plain numbers: the formula becomes

If you want, you can simplify it by expanding the square and then multiply the two parenthesis:

Answer:
the classmate is incorrect
Step-by-step explanation:
when you do the math for both inequalities they are equal to each other, despite the fact that one has multiplication and the other has addition.
X = 28
1/4+17=x-4
Multiply both sides of the equation by 4
X+68=4z-16
Move variable to the left hand side and change its sign
X-4x+68=-16
X-4x=-16-68
Combine like terms
-3x=-16-68
-3x=-84
Divide both sides by -3
X=28