\(a,573+67-\left(573-23\right)\\ =573+67-573+23\\=\left(573-573\right)+\left(67+23\right)\\ =0+90\\ =90\\ b,\left(-73\right)-\left[2^3.5-6\right].2\\ =\left(-73\right)-\left[8.5-6\right].2\\ =\left(-73\right)-\left[40-6\right].2\\ =\left(-73\right)-34.2\\ =\left(-73\right)-68\\ =-141\)
\(573+67-\left(573-23\right)\)
\(=573+67-573+23\)
\(=\left(573-573\right)+\left(67+23\right)\)
\(=0+90=90\)
\(------------\)
\(\left(-73\right)-\left(2^3.5-6\right).2\)
\(=\left(-73\right)-\left(8.5-6\right).2\)
\(\left(-73\right)-34.2\)
\(=\left(-73\right)-68=-141\)
a,573+67−(573−23)=573+67−573+23=(573−573)+(67+23)=0+90=90b,(−73)−[23.5−6].2=(−73)−[8.5−6].2=(−73)−[40−6].2=(−73)−34.2=(−73)−68=−141
