math
posted by Anonymous .
Explain an error problem in each of the following:
a) 13/35=1/5, 27/73 = 2/3, 16/64 = 1/4
b) 4/5+2/3=6/8, 2/5+3/4=5/9, 7/8+1/3=8/11
c) 8 3/86 1/4=2 2/4, 5 3/82 2/3=3 1/5, 2 2/71 1/3=1 1/4
d) 2/3*3=6/9, 1/4*6=6/24, 4/5*2=8/10

What fun!
a) You can cancel out numbers that are common to the top and bottom of a fraction... but you can't cancel individual digits!
b) These examples suggest that a/b + c/d = (a+c)/(b+d). Wrong!
c) These examples suggest that {a+(b/c)}  {d+(e/f)} = {(ad) + (be)/(fd)}. Also wrong!
d) These examples suggest that a*(b/c) = (a*b)/(a*c). Wrong yet again! 
Oops: I've got the last bit of the explanation of c) incorrect, but I'm sure you can correct it.