Question 705939
{{{(-3/5)(-4/21)}}}
First, you figure out if the product will have a minus sign.
If both factors have the same sign, the product is positive,
so no minus sign is needed.
{{{(-3/5)(-4/21)=(3/5)(4/21)}}}
Now, when we multiply fractions,
we multiply the numerators (the top parts) to get the numerator of the result,
and we multiply the denominators (the bottom parts) to get the denominator of the result.
{{{(3/5)(4/21)=3*4/(5*21)}}}
At this point we see if we can simplify,
because it is easier to simplify at this point than afterwards.
{{{21=3*7}}} so we can write it as that
{{{3*4/(5*21)=3*4/(5*3*7)}}}
Then we can cross out the 3's and end up with {{{4/5/7=highlight(4/35)}}}
because {{{3/3=1}}} and
{{{3*4/(5*3*7)=3*4/(3*5*7)=(3/3)(4/5/7)=(1)(4/5/7)=4/5/7}}}