\(\frac{5}{15}=\frac{5\div5}{15\div5}=\frac{1}{3}\)\(;\)\(\frac{8}{48}=\frac{8\div8}{48\div8}=\frac{1}{6}\)\(;\)\(\frac{7}{42}=\frac{7\div7}{42\div7}=\frac{1}{6}\)

22 - 100 - 400 = -478

D.among

đúng ko

x + 12 = 79 - 25

x + 12 = 54

x        = 54 - 12

x        = 42