Question

Bài 1:

a) (-127).57 + (-127).43

b) -13 .34 - 87.34

c)(-25).68 + (-34).(-250)

d)1 - 2 - 3 +4 +5 -6 -7 +........+97 -98-99 +100

 

Answer 1

a) ( - 127 ) . 57 + ( - 127 ) . 43

= ( - 127 ) . ( 57 + 43 )

= ( - 127 ) . 100

= - 12 700

b) - 13 . 34 - 8 . 34

=  ( - 13 - 8 ) . 34

= - 21 . 34 = - 714

c) ( - 25 ) . 68 + ( - 34 ) . ( - 250 )

=  ( - 25 ) . 68 + ( - 340 ) . ( - 25 )

= ( - 25 ) . [ 68 + ( - 340 ) ]

= ( - 25 ) . - 272

= 6800

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Answer 2

\(a,\left(-127\right).57+\left(-127\right).43\)

\(=\left(-127\right).\left(57+43\right)\)

\(=\left(-127\right).100\)

\(=-12700\)

\(b,-13.34-87.34\)

\(=34.\left(-13-87\right)\)

\(=34.\left(-100\right)\)

\(=-3400\)

\(c,\left(-25\right).68+\left(-34\right).\left(-250\right)\)

\(=\left(-25\right).68+\left(-34\right).10.\left(-25\right)\)

\(=\left(-25\right).68+\left(-340\right).\left(-25\right)\)

\(=\left(-25\right).\left(68-340\right)\)

\(=\left(-25\right).\left(-272\right)\)

\(=6800\)

Answer 3

a, (-127) . 57 + (-127) . 43

= (-127) .( 57 + 43 )

=(-127) .100

= -12700

b,-13 . 34 - 87 . 34

= 34 . [ ( -13 ) - 87 ]

= 34 . (-100)

= -3400

c, (-25) . 68 + (-34) .(-250)

= (-25) . 68 + (-34) . 10 . (-25) 

= (-25) . 68+ (-340) . (-25)

= (-25) . ( -340 +68 )

= (-25) . (-272)

= 6800