Answer:
Step-by-step explanation:
Least common denominator of 4 & 8 = 8
[tex]\frac{-1}{4}+\frac{-3}{8}=\frac{-1*2}{4*2}+\frac{-3}{8}\\\\=\frac{-2}{8}+\frac{-3}{8}\\\\=\frac{-2+[-3]}{8}\\\\=\frac{-5}{8}[/tex]