How do you find the product of #-3(4.2)#?

1 Answer
Apr 8, 2015

I would write it as #-1*[3xx4.2]# and use the usual "column" multiplication as:
#4.2xx#
#3=#
#126#
Multiplied by #-1# gives #-126#
To place the decimal point you count the decimal places of your factors and move the point from right to left accordingly.
In this case you have only one decimal place (#.2#) so you can place the decimal point before the #6# getting:
#-12.6#

hope it helps