How do you simplify #5.2-2.09#?

2 Answers
Dec 16, 2016

Answer:

I got #3.11#

Explanation:

I would write it as:

#520/100-209/100=(520-209)/100=311/100=#

dividing by #100# we get (moving the point from right to left):

#311/100=3.11#

Dec 16, 2016

Answer:

#3.11#

Explanation:

Consider the 0.2 from 5.2

But this is the same as #2/10# and can be written as:

#0.2=1/10+[1/10color(green)(xx1)]#

#0.2=1/10+[1/10color(green)(xx10/10)]#

#0.2=(color(magenta)(1))/10+[(color(magenta)(10))/100]#

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
How is this translated into something we can use? Do this:

#5.20#
#ul(2.09)larr" subtract"#

#5. cancel(2)^(color(magenta)(1))cancel(0)^(color(magenta)(10))#
#ul(2. color(white)(.)0color(white)(.)9)larr" subtract"#
#3. color(white)(.)1color(white)(.)1#