\(a,5\dfrac{3}{4}+\dfrac{-8}{9}=\dfrac{23}{4}+\dfrac{-8}{9}=\dfrac{207}{36}+\dfrac{-32}{36}=\dfrac{175}{36}\)
\(b,3\dfrac{3}{4}:2\dfrac{1}{2}=\dfrac{15}{4}:\dfrac{5}{2}=\dfrac{15.2}{4.5}=\dfrac{3.5.2}{2.2.5}=\dfrac{3}{2}\)
\(c,\dfrac{-9}{5}:1,2=\dfrac{-9}{5}:\dfrac{6}{5}=\dfrac{-9.5}{5.6}=\dfrac{-3.3}{3.2}=-\dfrac{3}{2}\)
\(d,\left(1,7\right)^{2023}:\left(1,7\right)^{2021}=\left(1,7\right)^{2023-2021}=\left(1,7\right)^2=2,89\)
b,334:212=154:52=15.24.5=3.5.22.2.5=32�,334:212=154:52=15.24.5=3.5.22.2.5=32
a)5\(\dfrac{3}{4}\)+\(\dfrac{-8}{9}\)
=\(\dfrac{23}{4}\)+\(\dfrac{-8}{9}\)
=\(\dfrac{207}{36}\)+\(\dfrac{-32}{36}\)
=\(\dfrac{175}{36}\)
b)3\(\dfrac{3}{4}\):2\(\dfrac{1}{2}\)
=\(\dfrac{15}{4}\):\(\dfrac{5}{2}\)
=\(\dfrac{3}{2}\)
c)\(\dfrac{-9}{5}\):1,2
=\(\dfrac{-9}{5}\):\(\dfrac{12}{10}\)
=\(\dfrac{-3}{2}\)