a
\(\dfrac{121.75.130.169}{39.60.11.198}\\ =\dfrac{11.11.5.5.3.13.2.5.13.13}{13.3.2.2.3.5.11.18.11}\\ =\dfrac{5.13.5.13}{2.3.18}\\ =\dfrac{65.65}{108}\\ =\)
tự tính
\(b\\ \dfrac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}.9.5^{11}.7^{11}}\\ =\dfrac{5^{11}.7^{11}.2.7}{5^{12}.7^{11}.7.9.5^{11}.7^{11}}\\ =\dfrac{2}{5^{12}.7^{11}.9.}\\ =\)\
tự tính nhé