a: \(-472+\left(235-28\right)-\left(35-350\right)\)

\(=-472+235-28-35+350\)

\(=\left(-472-28\right)+\left(235-35\right)+350\)

=-500+350+200

=50

b: \(91\cdot172+91\cdot13-91\cdot85\)

\(=91\cdot\left(172+13-85\right)\)

\(=91\cdot100=9100\)

c: \(798-298:\left[19-2\left(5^2-22\right)^2\right]\cdot1^{2023}\)

\(=798-298:\left[19-2\left(25-22\right)^2\right]\)

\(=798-298:\left[19-2\cdot3^2\right]\)

\(=798-298:\left(19-18\right)\)

=798-298

=500

-472 + (235 - 28) - 35 - 350

= -472 + 207 - 35 - 350

= -265 - 35 - 350

= 300 - 350 = -50

-50

bằng -650

a: -127+208-73+92

\(=\left(-127-73\right)+\left(208+92\right)\)

\(=300-200=100\)

b: \(-46+391+246-691\)

\(=\left(-46+246\right)+\left(391-691\right)\)

\(=200-300=-100\)

c: \(-472+\left(235-28\right)-\left(35-350\right)\)

\(=-472+235-28-35+350\)

\(=\left(-472-28\right)+350+\left(235-35\right)\)

\(=-500+350+200=50\)

a) -127+208-73+92

b) 

c) 

200 x 100 + 350 - 346 = 20000 + 350 - 346 = 20350 - 346 = 20005

200 x 100+350 - 346=20000+350-346=20350-346=20004

(100+235) x 2-70=335 x 2-70=670-70=600

100 x 300 x 234 x 450=30000 x 234 x 450=7020000 x 450=3159000000

\(=\left[\left(-6x\right)+\left(x^2+9\right)\right]\left[\left(-6x\right)-\left(x^2+9\right)\right]\)

\(=\left(-6x\right)^2-\left(x^2+9\right)^2\)

\(=36x^2-\left(x^4+18x^2+81\right)\)

\(=-x^4+18x^2-81\)

\(=-\left(x^4-18x^2+81\right)\)

\(=-\left(x^2-9\right)^2\)

Ta có: \(\left(x^2-6x+9\right)\left(-x^2-6x-9\right)\)

\(=-\left(x^2-6x+9\right)\left(x^2+6x+9\right)\)

\(=-\left[\left(x-3\right)^2\cdot\left(x+3\right)^2\right]\)

\(=-\left(x^2-9\right)^2\)