hi yaz white sheep!!!!

1a) yes ur right!!!  hooray for you!!!!!

1b) awwww..... u missed it by one mistake.  use the properties of multiplication by negatives:
           -1(-1)=+1          -1(1)=-1           -(a-b)=-a+b
      try and finish the problem knowing the above.

2a) (a+b)(a-b)
      = a(a) + a(-b) + b(a) + b(-b)
      = a² -ab + ab -b²
      = a² - b²

2b) (a+b)(b+c)(c+d)
      = (ab + ac + b² + bc)(c+d)
      = abc + abd + ac² + acd + b²c + b²d + bc² + bcd

3a) i will let u solve this one.  use the following properties:
             a/a = 1      the a's cancel out   

            (a-b)/(a-b) = 1    same thing here

3b) 1 - z = 4z - 9
      step 1) tranfer all of the z's onto one side:
                 1 -z + z = 4z + z - 9
                 1 = 4z + z - 9
                 1 = 5z - 9
           (remember: if you want to move something to the other side you must do the opposite of it's         
            sign to both sides)

        step 2) move all of the constants to the other side and solve for z:
                 1 + 9 = 5z - 9 + 9
                 10 = 5z
                 (10)/5 = (5z)/5
                   2 = z

2d)    (z-1)/(z+3) = (2z+3)/(2z-3)
                 
        use the following property:
           a/b = c/d
           a(d) = c(b)
           
          (z-1)(2z-3) = (2z+3)(z+3)

try and work out the last one.  if you run into trouble you know where to get help!!

c yaz!

Last edited by Flowers4Carlos (2005-10-15 05:08:24)