a = (81+19)+35

=100+35=135

b = (78+22)+(65+135)

=100+200=300

c = (234+17716)+23

=17950+23=17973

d = (99+1)+85

=100+85=185

a) 81 + 35 + 19 = (81 + 19) + 35 = 100 + 35 = 135

b) 78 + 65 + 135 + 22 = (78 + 22) + (135 + 65) = 100 + 200 = 300

c) 234 + 17716 + 23 = 17950 + 23 = 17973

d) 85 + 99 + 1 = 85+ (99 + 1) = 85 + 100 = 185

khó quá đi!!

\(a,-55.78+13\left(-78\right)-78.\left(-65\right)\)

\(=78\left(-55-13+65\right)\)

\(=78.\left(-3\right)\)

\(=-234\)

\(b,45\left(-24\right)+\left(-10\right).\left(-12\right)\)

\(=-90.\left(-12\right)+\left(-10\right).\left(-12\right)\)

\(=-12\left(-90-10\right)\)

\(=-12.\left(-100\right)\)

\(=1200\)

a) \(-55.78+13.\left(-78\right)-78.\left(-65\right)\)

\(=\left(55+13-65\right).\left(-78\right)\)

\(=-234\)

b) \(45.\left(-24\right)+\left(-10\right).\left(-12\right)\)

\(=45.\left(-24\right)+\left(-10\right):2.2.\left(-12\right)\)

\(=45.\left(-24\right)+\left(-5\right).\left(-24\right)\)

\(=\left(-24\right).\left(45-5\right)\)

\(=-960\)

a) \(\left(81+19\right)+35=135\)

b) \(\left(78+22\right)+\left(65+135\right)=100+200=300\)

c) \(\left(234+17716\right)+23=17950+23=17973\)

d) \(\left(99+1\right)+85=100+85=185\)

\(a,81+35+19=\left(81+19\right)+35=100+35=135\\ b,78+65+135+22=\left(78+22\right)+\left(65+135\right)=100+200=300\\ c,234+17716+23=\left(234+17716\right)+23=17950+23=17973\\ d,85+99+1=85+\left(99+1\right)=85+100=185\)

1: \(=-24\left(45-5\right)=-24\cdot40=-960\)

2: \(=-134\left(1-51+48\right)=-134\cdot\left(-2\right)=268\)

3: \(=124\left(1-52+47\right)=124\cdot\left(-3\right)=-372\)

a: \(\left(-134\right)+51\cdot134+\left(-134\right)\cdot48\)

\(=134\left(-1+51-48\right)=134\cdot2=268\)

b: \(124+\left(-52\right)\cdot124+\left(-124\right)\cdot\left(-47\right)\)

\(=124-52\cdot124+124\cdot47\)

\(=124\left(1-52+47\right)=124\cdot\left(-4\right)=-496\)

c: \(-55\cdot78+13\cdot\left(-78\right)-78\cdot\left(-65\right)\)

\(=78\cdot\left(-55\right)-78\cdot13+78\cdot65\)

\(=78\left(-55-13+65\right)=78\cdot\left(-3\right)=-234\)

d: \(45\cdot\left(-24\right)+\left(-10\right)\cdot\left(-12\right)\)

=-1080+120

=-960

thanks

b) \(-55.78+13.\left(-78\right)-78.\left(-65\right)\)

\(=55.\left(-78\right)+13.\left(-78\right)-65.\left(-78\right)\)

\(=\left(-78\right).\left(55-65+13\right)\)

\(=\left(-78\right).3\)

\(=-234\)

ai làm nhanh tui k cho ạ, giúp vs đang cần gấp

-234-(123-234)

= -234-123+234

= 123

a.(-256).43+(-256).25-256.32                            
=(-256).43+(-256).25+(-256).32                =(-256).(43+25+32)    
=(-256).100      
-25600