Question

mọi người ơi, giúp mik với( gấp lắm luôn)

Answer 1

\(=-\dfrac{7}{4}.(\dfrac{5}{21}+\dfrac{7}{21})\)

\(=-\dfrac{7}{4}.\dfrac{12}{21}\)

\(=-1\)

Answer 2

a) \(=\left(-\dfrac{7}{4}\right).\left(\dfrac{5}{21}+\dfrac{7}{21}\right)=\left(-\dfrac{7}{4}\right).\dfrac{4}{7}=-1\)

b) \(=\dfrac{1}{5}:\left(\dfrac{-3}{10}\right)^2=\dfrac{1}{5}.\dfrac{100}{9}=\dfrac{20}{9}\)

c) \(=2-0+4.2=2+8=10\)