Expert: Richard J. Raridon - 6/13/2006

Question
these are some of the problems ive been having trouble with.maybe you can help

1)  find the L.C.D.
    3/a,3/b,1/5

2) indicate which of the following sets of lines are parallel,perpindicular,or neither and could you show the work so i can see how you did it

a)  y=2x-5
   y=2x+5   __________

b)  3x+y=5
   -x+3y=6  __________

c)  3x+y=5
    x+y=3    __________

3)write an equation for the line with slope 3 going through the point (1,-2)
4)write an equation for the line going through the points (3,2)and(-2,4)

5)how would i graph the equation x-y=6
6)how would i graph the function y=f(x)=x^2

could you also show how you did it on these ones,they want me to
a.determine how many x-intercepts the parabola has
 b.whether its vertex lies above or below or on the x-axis.

7)y=x^2-5x+6



8)y=-x^2+2x-1


and solve the following leaving answers in simplest radical form

9)x^2+8x=-16
10)3x^2=2x+5  

Answer
1) 5ab
2) re-write each of them in standard form, y = mx+b, where m is the slope.
a) slope is the same so lines are parallel
b) y = -3x+5 and y = (1/3)x +2
one slope is the negative reciprocal of the other so lines are perpendicular
c) y = -3x+5 and y = x+3, lines are neither
3) -2 = 3(1)+b so the line is y = 3x-5
4) 2 = 3m+b and 4 = -2m+b so line is 2x+5y = 16
5) this is a straight line so it only takes two points to plot it.  they could be (10,4) and (6,0)
6) this is a parabola.  just put in values for x, calculate y, and plot.  two points are (0,0) and (1,1)
7) a) y = x^2-5x+6 = (x-2)(x-3) so it has two intercepts.
b) plot a few points to see where the vertex is
8) a) y = -(x-1)^2 so it has only one intercept
b) again, plot a few points
9) x^2 +8x +16 = (x+4)^2 so x=-4
10) 3x^2 -2x -5 = (3x-5)(x+1) so x = 5/3, -1