Algebra/Math
posted by Karen on .
Can you check these for me.
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
4xy=3
Answer: parallel
7. 6x9y=4
2/3xy=11
Answer: perpendicular
8. y7=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

Question 15:
slope is tangens of angle betwen xaxis and line.
Equation is:
tan(alpha)=(y2y1)/(x2x1)
Firs 5 question is O.K 
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) 
Question 6
(1/2)x+2y=1 , 2y=(1/2)x+1
(Divided with 2) y=(1/4)x+1/2
Slope(1/4)
4xy=3 , y=4x3 (Slope 4)
Perpendicular 
Question 7
6x9y=4 , 9y=6x*4 (Divided with 9)
y=(6/9)x4/9
y=(2/3)x4/9 Slope (2/3)
(2/3)xy=11 , y=(2/3)x11 Slope (2/3)
Parallel 
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=4x3
For question 7 draw lines
(2/3)x4/9 and (2/3)x11 
Question 8
y7=0 y=7
For all values of x y=7
That is line parallel with xaxis
3x=5 (divided with 3)
x=5/3
For all values of y x=5/3
That is line p0arallel with yaxis 
3x(5(108)