123456789+123456789+12+34+56+78+90+1234567890+9087654321 = 10569136059

những câu hỏi linh tinh

câu 1:

\(\left\{1;2;...;11\right\}\)

\(\left\{x\in N;0< x\le11\right\}\)

câu 2:

a) \(=416-\dfrac{189}{32}=\dfrac{13123}{32}\)

b) dãy trên có số hạng là: \(\left(90-12\right):3+1=27\)(số)

tổng dãy số trên là:\(\left(90+12\right).27:2=1377\)

c) \(=2020-\left(45-5^2\right)+1=2020-20+1=2001\)

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

Câu 13: 

A={1;2;3;4;5;...;11}

A={x∈N|0<x<12}

\(a.13.\left(78+22\right)=13.100=1300\)

\(b.25.70+28.25+25.2=25.\left(70+28+2\right)=25.100=2500\)

\(c.\dfrac{15.3.14.2.19}{19.14.15}=6\)

\(d.\dfrac{132.70.60}{12.35.20}=\dfrac{11.12.35.2.20.3}{12.35.20}=66\)

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

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

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

\(=-234\)

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

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

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

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

\(=1200\)

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

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

\(=-234\)

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

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

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

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

\(=-960\)

B4

a)x=10

b)x=3

c)x=11

d)x=8

1.

a. 

11 + x : 5 = 13 

x : 5 = 13 - 11

x : 5 = 2

x      = 2 . 5

x      = 10

cọu lên gg í <<:

??????????!

1+2+3+4+....-56+56+48.......-23+56+586=6928

=6978 nha bn