3−3⋅1931935⋅19−32=?
Let's start by simplifying the second term in the complete multiplication, meaning - the fraction. We'll simplify it in two stages:
In the first stage we'll use the power law for multiplication between terms with identical bases:
and simplify the fraction's numerator:
Next, we can either remember that dividing any number by itself gives 1, or use the power law for division between terms with identical bases:
to get that:
where in the last step we used the fact that raising any number to the power of 0 gives 1, meaning mathematically that:
Let's summarize this part, we got that:
Let's now return to the complete expression in the problem and substitute this result in place of the fraction:
In the next stage we'll recall the power law for negative exponents:
and apply this law to the result we got:
Summarizing all the steps above, we got that:
Therefore the correct answer is answer A.