Can you check these for me.

Question

Directions: Find the slope of the line that passes through each pair of points.

1. (3,-8) and (-5,2)
Answer: -10/8

2. (-10,-3) and (7,2)
Answer: -5,-17

3. (-7,-6) and (3,-6)
Answer: 9

4. (8,2) and (8,-1)
Answer: 0 undefined

Directions: State whether the graphs of the following equations are parallel, perpendicular, or neither.

5. 2x+3y=4
3x+2y=6
Answer: parallel

6. 1/2x+2y=1
4x-y=3
Answer: parallel

7. 6x-9y=4
2/3x-y=11
Answer: perpendicular

8. y-7=0
3x=5
Answer: neither

Math Problem: A pyramid of aluminum cans is built against a wall so that there are two cans in the top row, four cans in the second row, six cans in the third row , and so on. How many rows are there if the pyramid contains 1190 cans?
Answer: 595 rows

Answer 1

Question 1-5:
slope is tangens of angle betwen x-axis and line.
Equation is:

tan(alpha)=(y2-y1)/(x2-x1)

Firs 5 question is O.K

Answer 2

Sorry. Answer for question 5 is not correct.
2x+3y=4 , 3y=-2x+4 (Divided with 3)
y=(-2/3)x+4/3 Slope (-2/3)

3x+2y=6 , 2y=-3x+6 (Divided with 2)
y=(-3/2)x+3 Slope(-3/2)

Answer 3

Question 6
(1/2)x+2y=1 , 2y=(-1/2)x+1
(Divided with 2) y=(-1/4)x+1/2
Slope(-1/4)

4x-y=3 , y=4x-3 (Slope 4)

Perpendicular

Answer 4

Question 7
6x-9y=4 , -9y=-6x*4 (Divided with -9)
y=(-6/-9)x-4/9
y=(2/3)x-4/9 Slope (2/3)

(2/3)x-y=11 , y=(2/3)x-11 Slope (2/3)

Parallel

Answer 5

Best way to check that is that you drive this lines in grid.Is enough 2 points for any lines.
For question 5 draw lines
(-2/3)x+4/3 and y=(-3/2)x+3
For question 6 draw lines
(-1/4)x+1/2 and y=4x-3
For question 7 draw lines
(2/3)x-4/9 and (2/3)x-11

Answer 6

Question 8
y-7=0 y=7
For all values of x y=7
That is line parallel with x-axis

3x=5 (divided with 3)
x=5/3
For all values of y x=5/3
That is line p0arallel with y-axis

Answer 7

3x(5-(10-8)