What is #85.65-:0.05#?

2 Answers
Aug 4, 2016

#85.65-:0.05=1713#

Explanation:

A division by any fraction, including decimal fraction, is equivalent to multiplication by its reciprocal also called multiplicative inverse.

The reciprocal or multiplicative inverse.of a fraction #a/b# is just #b/a#, as their product is #1#, the identity element for multiplication.

Hence we can write #85.65-:0.05#

= #8565/100-:5/100#

= #8565/100xx100/5#

= #(1713cancel8565)/cancel100xx(cancel100)/(1cancel5)#

= #1713#

Aug 5, 2016

#1713#

Explanation:

The simple answer to a question involving division by a decimal is..
"you can't#

Change it into a division by a whole number.

#85.65/0.05 xx 100/100 = 8565/5#

This is allowed because #100/100 = 1# and multiplication by 1 does not change the value.We have only changed what it looks like.

Both the top and bottom were multiplied by 100.

#8565/5# now divide as usual.

=#1713#