$Bài1$:
$a$.$\frac{75}{100}$+$\frac{18}{21}$+$\frac{19}{32}$+$\frac{1}{4}$+$\frac{3}{21}$+$\frac{13}{32}$
=($\frac{75}{100}$+$\frac{1}{4}$)+($\frac{18}{21}$+$\frac{3}{21}$)+($\frac{19}{32}$)+($\frac{13}{32}$)
=($\frac{75}{100}$+$\frac{25}{100}$)+$1$+$1$
=$1$+$1$+$1$
=$3$
$b$.$\frac{6:\frac{3}{5}-1\frac{1}{6}×\frac{6}{7}}{4\frac{1}{5}×\frac{10}{11}+5\frac{2}{11}}$ =$\frac{6×\frac{5}{3}-\frac{7}{6}×\frac{6}{7}}{\frac{21}{5}×\frac{10}{11}+\frac{57}{11}}$ =$\frac{\frac{3×2×5}{3}-\frac{7×6}{6×7}}{\frac{21×2×5}{5×11}+\frac{57}{11}}$ =$\frac{10-1}{\frac{42}{11}+\frac{57}{11}}$ =$\frac{9}{\frac{99}{11}}$ =$\frac{9}{9}$=$1$
bài 2:
b. x=291
còn phần a,c,d,e mk lm ra giấy nhé.
