How to write 4/10 as a product of a whole number and a unit fraction

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?

Miranda is braiding her hair. then she will attach beads to the braid. she wants 1_3 of the beads to be red. if the greatest number of beads that will fit on the braid is 12,what other fractions could represent the part of the beads that are red?

On #16 : explain how factoring a trinomial, ax^2+ bx+ c, when a does not equal 1 different from factoring a trinomial when a = 1.