-[tex] \frac{3}{10} [/tex] × -[tex] \frac{5}{12} [/tex]
=[tex] \frac{15}{120} [/tex]
Note that it is [tex] \frac{15}{120} [/tex] not -[tex] \frac{15}{120} [/tex] since two negatives will cancel each other out.
Now we need to simplify [tex] \frac{15}{120} [/tex]. We do this by dividing by the greatest common factor. I'll use the guess and check method, but there are other methods that you could also use.
[tex] \frac{15}{120} [/tex] ÷ [tex] \frac{15}{15} [/tex]
=[tex] \frac{1}{8} [/tex]
Your answer would be [tex] \frac{1}{8} [/tex]
