a) 25.69+31.25-25.6

= 25.(69+31-6)

= 25.94

= 2350

b) 198:[130-(27-19)²]+2021⁰

= 198:[130-8²]+1

= 198:(130-64)+1

= 198:66+1

= 3+1

= 4

c) 5²⁰:[5¹⁵.(15+10)]

= 5²⁰:[5¹⁵.25]

= 5²⁰:(5¹⁵.5²⁾

= 5²⁰: 5¹⁷

= 5³

a: =25x100-150=2500-150=2350

c: \(=520:\left\{515\cdot25\right\}\)

=104/2575

=198:(130-8²)+1
=198:66+1
=3+1
=4

198 : [130 – (27 – 19 )^2] + 2021^0

= 198: [130 - 8^2] + 1

= 198 :( 130- 64) +1

= 198: (66) +1

= 3+1=4

4

=4

4

b: =20+49-289=20-240=-220

1)tính

a)\(-18+\left(-19\right)+27\)

\(=-18-19+27\)

\(=-\left(18+19\right)+27\)

\(=-37+27\)

\(=-\left(37-27\right)\)

\(=-10\)

b)\(-198-194+286\)

\(=-\left(198+194\right)+286\)

\(=-392+286\)

\(=-\left(392-286\right)\)

\(=-6\)

c)\(-19-\left(-17\right)\)

\(=-19+17\)

\(=-\left(19-17\right)\)

\(=-2\)

d)\(-48+\left(-47\right)-\left(-15\right)\)

\(=-48-47+15\)

\(=-\left(48+47\right)+15\)

\(=-95+15\)

\(=-\left(95-15\right)\)

\(=-80\)

e)\(23-\left(-16\right)+\left(-80\right)\)

\(=23+16-80\)

\(=39-80\)

\(=-80+39\)

\(=-\left(80-39\right)\)

\(=-41\)

f)\(99-\left(-99\right)-198\)

\(=99+99-198\)

\(=198-198\)

\(=0\)

a. =-10

b. =-106

c. =-2

d. =-80

e. =-41

f. =0

=80-131+81+1

=31

=80-131+81+1

=31

2⁴.5- [ 131 - ( 13- 4)²]  + 2021⁰= 16.5 - [ 131 - 9² ] + 1 = 80 - 50 +1 = 31