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d) ( - 15 ) - 23 + ( - 85 ) - 77
= ( - 15 - 85 ) - ( 23 + 77 )
= - 100 - 100
= - 200
e) ( 123 - 37 ) - 123
= ( 123 - 123 ) - 37
= 0 - 37
= - 37
f) ( - 224 ) - ( 34 - 224 )
= ( - 224 + 224 ) - 34
= 0 - 34
= - 34
g) 126 - ( 126 - 33 )
= ( 126 - 126 ) - 33
= 0 - 33
= - 33
h) ( - 53 - 23 ) - ( 567 - 53 )
= ( - 53 + 53 ) + ( - 23 - 567 )
= 0 - 590
= - 590
d) ( - 15 ) - 23 + ( - 85 ) - 77
= ( - 15 - 85 ) - ( 23 + 77 )
= - 100 - 100
= - 200
e) ( 123 - 37 ) - 123
= ( 123 - 123 ) - 37
= 0 - 37
= - 37
f) ( - 224 ) - ( 34 - 224 )
= ( - 224 + 224 ) - 34
= 0 - 34
= - 34
g) 126 - ( 126 - 33 )
= ( 126 - 126 ) - 33
= 0 - 33
= - 33
h) ( - 53 - 23 ) - ( 567 - 53 )
= ( - 53 + 53 ) + ( - 23 - 567 )
= 0 - 590
= - 590
a) \(B=3+3^2+3^3+...+3^{120}\)
\(B=3\cdot1+3\cdot3+3\cdot3^2+...+3\cdot3^{119}\)
\(B=3\cdot\left(1+3+3^2+...+3^{119}\right)\)
Suy ra B chia hết cho 3 (đpcm)
b) \(B=3+3^2+3^3+...+3^{120}\)
\(B=\left(3+3^2\right)+\left(3^3+3^4\right)+\left(3^5+3^6\right)+...+\left(3^{119}+3^{120}\right)\)
\(B=\left(1\cdot3+3\cdot3\right)+\left(1\cdot3^3+3\cdot3^3\right)+\left(1\cdot3^5+3\cdot3^5\right)+...+\left(1\cdot3^{119}+3\cdot3^{119}\right)\)
\(B=3\cdot\left(1+3\right)+3^3\cdot\left(1+3\right)+3^5\cdot\left(1+3\right)+...+3^{119}\cdot\left(1+3\right)\)
\(B=3\cdot4+3^3\cdot4+3^5\cdot4+...+3^{119}\cdot4\)
\(B=4\cdot\left(3+3^3+3^5+...+3^{119}\right)\)
Suy ra B chia hết cho 4 (đpcm)
c) \(B=3+3^2+3^3+...+3^{120}\)
\(B=\left(3+3^2+3^3\right)+\left(3^4+3^5+3^6\right)+\left(3^7+3^8+3^9\right)+...+\left(3^{118}+3^{119}+3^{120}\right)\)
\(B=\left(1\cdot3+3\cdot3+3^2\cdot3\right)+\left(1\cdot3^4+3\cdot3^4+3^2\cdot3^4\right)+...+\left(1\cdot3^{118}+3\cdot3^{118}+3^2\cdot3^{118}\right)\)
\(B=3\cdot\left(1+3+9\right)+3^4\cdot\left(1+3+9\right)+3^7\cdot\left(1+3+9\right)+...+3^{118}\cdot\left(1+3+9\right)\)
\(B=3\cdot13+3^4\cdot13+3^7\cdot13+...+3^{118}\cdot13\)
\(B=13\cdot\left(3+3^4+3^7+...+3^{118}\right)\)
Suy ra B chia hết cho 13 (đpcm)
d) ( - 15 ) - 23 + ( - 85 ) - 77
= ( - 15 - 85 ) - ( 23 + 77 )
= - 100 - 100
= - 200
e) ( 123 - 37 ) - 123
= ( 123 - 123 ) - 37
= 0 - 37
= - 37
f) ( - 224 ) - ( 34 - 224 )
= ( - 224 + 224 ) - 34
= 0 - 34
= - 34
g) 126 - ( 126 - 33 )
= ( 126 - 126 ) - 33
= 0 - 33
= - 33
h) ( - 53 - 23 ) - ( 567 - 53 )
= ( - 53 + 53 ) + ( - 23 - 567 )
= 0 - 590
= - 590
tui chỉ viết bài làm thôiii
d
-15+(-85)-23-77=100-100=0
e
123-37-123=123-123-37=-37
g
126-126+33=33
f
-224-34+224=-224+224-34=-34
h
-53-23-567+53=-53+53-23-567=-23-567=-590
a) -37+1526-(213-37)
=-37+1526-213+37
=[(-37)+37]+1526-213
=1313
b) 2.37+(29-137)-53:19
=74-108-
a: \(=\dfrac{-12}{7}\left(\dfrac{4}{35}+\dfrac{31}{35}\right)-\dfrac{2}{7}=\dfrac{-12}{7}-\dfrac{2}{7}=-2\)
b: =(-4)+(-4)+...+(-4)
=-4*25=-100
c: \(=157\cdot\left(-37\right)-41\cdot53+37\cdot157+51\cdot53\)
=10*53
=530
a)Ta có:
\(\frac{419}{-723}< 0< \frac{-697}{-313}\)
\(\Rightarrow\frac{419}{-723}< \frac{-697}{-313}\)
c)\(\frac{17}{215}>\frac{17}{314}\)
d)Ta có:
\(\frac{11}{54}< \frac{22}{54}< \frac{22}{37}\)
\(\Rightarrow\frac{11}{54}< \frac{22}{37}\)
e)Ta có:
\(\frac{-385}{-126}>0>\frac{-57}{3461}\)
\(\Rightarrow\frac{-385}{-126}>\frac{-57}{3461}\)
f)Ta có:
\(\frac{123}{109}>1>\frac{556}{789}\)
\(\Rightarrow\frac{123}{109}>\frac{556}{789}\)
g)Ta có:
\(\frac{-56}{57}>-1>\frac{-49}{47}\)
\(\Rightarrow\frac{-56}{57}>\frac{-49}{47}\)
a ) Ta có :
\(\frac{450}{463}=1-\frac{13}{463}\) ( 1 )
\(\frac{123}{126}=1-\frac{3}{126}\)( 2 )
Từ ( 1 ) và ( 2 ) thấy 13/463 > 3/126 do đó 450/463 < 123/126
Vậy 450/463 < 123/126
b ) Ta có :
\(\frac{36}{53}=1-\frac{17}{53}\)( 1 )
\(\frac{58}{89}=1-\frac{31}{89}\)( 2 )
Từ 1 và 2 thấy 31/89 > 17/53 => 35/53 > 58/89
Vậy 35/53 > 58/89
(-4;-3;-2;-1;0;1;2;3;4)
Ko có dấu ngoặc nhọn nên mik xài ngoặc tròn nha
a) (123 - 37) -123 -123 - 37 -123 = (123 -123) - 37 = -37.
b) (-224) - (34 - 224) = -224 - 34 + 224 - (-224 + 224) - 34 = -34.
c) 126 - (126 - 33) = 126 -126 + 33 = 33.
d) (-53 - 23) - (567 - 53) - -53 - 23 - 567 + 53 = -590
a) (123 - 37) -123 -123 - 37 -123 = (123 -123) - 37 = -37.
b) (-224) - (34 - 224) = -224 - 34 + 224 - (-224 + 224) - 34 = -34.
c) 126 - (126 - 33) = 126 -126 + 33 = 33.
d) (-53 - 23) - (567 - 53) - -53 - 23 - 567 + 53 = -590