Let's make this a fractional division problem.
Simplify -15/100 to -3/20
\({-12\over5}/{-3\over20}\)
Flip the second fraction and change to multiplication.
\({-12\over5}*{-20\over3}\)
Multiply the numerators by each other and the denominators by each other.
\({-12\over5}*{-20\over3}={240\over15}\)
240/15 = 16, so \({-12\over5}/{-3\over20}=16\)
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