`(-3 .7^4 + 7^3)/(7^5 .6 -7^3 .2)`
`=(7^3 .(-3.7 +1))/(7^3 (7^2 .6 -2))`
`=(-20)/292=-5/73`
Giải:
\(\dfrac{-3.7^4+7^3}{7^5.6-7^3.2}\)
\(=\dfrac{-3.7.7^3+7^3}{7^3.7^2.6-7^3.2}\)
\(=\dfrac{7^3.\left(-3.7+1\right)}{7^3.\left(7^2.6-2\right)}\)
\(=\dfrac{-21+1}{49.6-2}\)
\(=\dfrac{-20}{294-2}\)
\(=\dfrac{-20}{292}=\dfrac{-5}{73}\)