Question

1) Rút gọn :

a) \(\frac{3.6+2.9.5+18.\left(-4\right)}{7.\left(-7\right)+12.\left(-7\right)+7}\)

b) \(\frac{2.3.4.5.6-3.4.5.6.7}{2.4.6-4.6.8}\)

           giải giupf mk với ....................................

ai giải giúp mk , mk sẽ tk ---------------------------------   giải 1 phần thui cũng đc

Answer 1

a) \(\frac{3.6+2.9.5+18.\left(-4\right)}{7.\left(-7\right)+12.\left(-7\right)+7}\)=\(\frac{18+18.5+18.\left(-4\right)}{-7.\left(7+12-1\right)}\)=\(\frac{18.\left(1+5-4\right)}{-7.18}\)=\(\frac{18.2}{18.\left(-7\right)}=\frac{-2}{7}\)

b) \(\frac{2.3.4.5.6-3.4.5.6.7}{2.4.6-4.6.8}=\frac{3.4.5.6.\left(2-7\right)}{4.6.\left(2-8\right)}\)=\(\frac{3.5.\left(-5\right)}{\left(-6\right)}=\frac{-25}{-2}=\frac{25}{2}\)

Answer 2

a)\(\frac{3.6+2.9.5+18.\left(-4\right)}{7.\left(-7\right)+12.\left(-7\right)+7}\)

\(=\frac{18+18.5+18.\left(-4\right)}{7.\left(-7\right)+\left(-12\right).7+7}\)

\(=\frac{18.\left(1+5+-4\right)}{7.\left(-7+-12+1\right)}\)

\(=\frac{15.2}{7.\left(-18\right)}\)

\(=\frac{3.5.2}{7.2.3.-3}\)

\(=\frac{5}{-21}\)

b) \(\frac{2.3.4.5.6-3.4.5.6.7}{2.4.6-4.6.8}\)

\(=\frac{3.4.5.6.\left(2-7\right)}{4.6.\left(2-8\right)}\)

\(=\frac{3.4.5.6.\left(-5\right)}{4.6.\left(-3\right)}\)

\(=\frac{3.5.\left(-5\right)}{\left(-3\right)}\)

\(=\frac{-75}{\left(-3\right)}\)

\(=25\)

Answer 3

tui như trên

a)-2/7

b)25/2=12.5