What is the quotient of -5.2/3.9?

2 Answers
Jan 5, 2017

Answer:

#-1 1/3#

Explanation:

#color(blue)("Simplify the fraction")#

Write as:#" " -(5.2/3.9)#

Don't like decimals so lets get rid of them.

#color(green)(-(5.2/3.9color(red)(xx1)) = -(5.2/3.9color(red)(xx10/10))#

#=- 52/39 #

Note that - 52 is the same as - 39 - 13

#-39/39 - 13/39" "=" "-1-1/3" " =" " -4/3#

But #" "-4/3" " =" " -3/3-1/3" " =" " -1 1/3#
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#color(blue)("Now compare this to "-(5.2-:3.9))#

Using a calculator we get #-1.3333333...#

which is the same as #-1 1/3#
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This is because:

#5.2/3.9 -> (5.2-:3.9)/(3.9-:3.9) = (5.2-:3.9)/1=(1.33333...)/1 = ( 1 1/3)/1=1 1/3#

Jan 5, 2017

Answer:

#-4/3 = -1 1/3 ~~ -1.333#

Explanation:

At a time when many students tend to depend on a calculator, many will not realise that working with fractions can be easier than using decimals, and there are often really simple methods to do calculations.

A quotient is the answer to a division

In this case:

#(-5.2)/3.9" "larr# dividing BY a decimal is not a good idea.

Get rid of the decimals by multiplying by #10/10#

#(-5.2)/3.9 xx 10/10 = (-52)/39#

This is where knowing the multiplication times tables helps.

#52 and 39# are both divisible by 13. Cancel to simplest form:

#(-52div13)/(39div 13) = (-4)/3#

This can be written as #-4/3 = -1 1/3 ~~ -1.333#