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a) \(\frac{2}{3}-4.\left(\frac{1}{2}+\frac{3}{4}\right)\)
= \(\frac{2}{3}-4.\frac{5}{4}\)
= \(\frac{2}{3}-5\)
= \(-\frac{13}{3}\).
b) Câu này là 117 hay \(\frac{11}{7}\) vậy bạn?
Chúc bạn học tốt!

A=(-3/4+2/3).11/9+(-1/4+1/3):|-9/11|
\(=\left(-\frac{3}{4}+\frac{2}{3}\right).\frac{11}{9}+\left(-\frac{1}{4}+\frac{1}{3}\right).\frac{11}{9}\)
\(=\frac{11}{9}\left(-\frac{3}{4}+\frac{2}{3}-\frac{1}{4}+\frac{1}{3}\right)\)
\(=\frac{11}{9}\left(-1+1\right)\)
\(=\frac{11}{9}.0\)
=0

a) \(\frac{1}{3}-\frac{3}{4}-\left(\frac{-3}{5}\right)+\frac{1}{64}-\frac{2}{9}-\frac{1}{36}+\frac{1}{15}\)
=\(\left(\frac{1}{3}+\frac{3}{5}+\frac{1}{15}\right)-\left(\frac{3}{4}+\frac{2}{9}+\frac{1}{36}\right)+\frac{1}{64} \)
=\(\frac{5+9+1}{15}-\frac{27+8+1}{36}+\frac{1}{64}\)
= \(1+1+\frac{1}{64}=2\frac{1}{64}\)

1. Tính hợp lí :
a) \(\frac{6}{7}.\frac{5}{11}+\frac{5}{7}.\frac{2}{11}-\frac{5}{7}.\frac{14}{11}\)
\(=\frac{5}{7}.\left(\frac{6}{11}+\frac{2}{11}-\frac{14}{11}\right)\)
\(=\frac{5}{7}.\frac{-6}{11}=-\frac{30}{77}\)
b) \(\frac{1}{3}.\frac{4}{5}+\frac{1}{3}.\frac{6}{5}-\frac{1}{3}\)
\(\frac{1}{3}.\left(\frac{4}{5}+\frac{6}{5}-\frac{1}{3}\right)\)
\(=\frac{1}{3}.\frac{5}{3}=\frac{5}{9}\)

Do x2n=(-x)2n
=>327.1530.(-4)16=327.(-15)30.416=327.(-15)30.(42)8=327.(-15)30.88
(327.1530.(-4)16)/((-15)30.811)=(327.(-15)30.88)/((-15)30.811)=327/83

a, -5/11.7/15.(11/-5)(-30)
=(-5/11.11/-5).(7/15.-30)
=1.7.(-30)/15
=1.7.(-2).15/15
=1.7.(-2)
=-14
b,(11/12):(33/36).3/5
=11/12:(11.3/12.3).3/5
=11/12:11/12.3/5
=1.3/5
=3/5
c,(-5/-9).3/11+(-13/18).3/11
=5/9.3/11+ -13/18.3/11
=3/11.(5/9+ -13/18)
=3/11.(10/18+ -13/18)
=3/11.-3/18
= -9/198
= -1/22
Bài 2:
a,-7/15.5/8.15/7.(-16)
=(-7/15.15/7)(5/8. -16)
= -1.-10
= 10
b,(-1/-2).16/5+(-1/-2)(-11/5)
= 1/2.16/5+1/2. (-11/5)
=1/2.(16/5+ -11/5)
=1/2.5/5
=1/2.1
=1/2
học tốt nha bạn. chúc bạn thành công

\(A=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{98.99}+\frac{1}{99.100}\)
\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)
\(A=1-\frac{1}{100}\)
\(A=\frac{99}{100}\)
\(B=\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+...+\frac{4}{107.111}\)
\(B=\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+...+\frac{1}{107}-\frac{1}{111}\)
\(B=\frac{1}{3}-\frac{1}{111}\)
\(B=\frac{12}{37}\)
\(C=\frac{7}{10.11}+\frac{7}{11.12}+\frac{7}{12.13}+...+\frac{7}{69.70}\)
\(C=7\left(\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}+...+\frac{1}{69}-\frac{1}{70}\right)\)
\(C=7\left(\frac{1}{10}-\frac{1}{70}\right)\)
\(C=7.\frac{3}{35}\)
\(C=\frac{3}{5}\)
Ta có:
\(A=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{98.99}+\frac{1}{99.100}\)
\(A=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{98}-\frac{1}{99}+\frac{1}{99}-\frac{1}{100}\)
\(A=\frac{1}{1}-\frac{1}{100}=\frac{99}{100}\)
\(B=\frac{4}{3.7}+\frac{4}{7.11}+\frac{4}{11.15}+...+\frac{4}{107.111}\)
\(B=4.\left(\frac{1}{3}-\frac{1}{7}+\frac{1}{7}-\frac{1}{11}+\frac{1}{11}-\frac{1}{15}+...+\frac{1}{107}-\frac{1}{111}\right)\)
\(B=4.\left(\frac{1}{3}-\frac{1}{111}\right)=4.\frac{12}{37}=\frac{48}{37}\)
\(C=\frac{7}{10.11}+\frac{7}{11.12}+\frac{7}{12.13}+...+\frac{7}{69.70}\)
\(C=7.\left(\frac{1}{10.11}+\frac{1}{11.12}+\frac{1}{12.13}+...+\frac{1}{69.70}\right)\)
\(C=7.\left(\frac{1}{10}-\frac{1}{70}\right)=7.\frac{3}{35}=\frac{3}{5}\)
1) x+14=43x+14=43
⇒x=43−14=1312⇒x=43−14=1312
2) 34:25.x=296034:25.x=2960
⇒25.x=2960−34=−415⇒25.x=2960−34=−415
⇒x=−415.52=−23⇒x=−415.52=−23
3) 134.x+112=−45134.x+112=−45
⇒74.x+32=−45⇒74.x+32=−45
⇒74.x=−45−32=−2310⇒74.x=−45−32=−2310
⇒x=−2310.47=−−4635⇒x=−2310.47=−−4635
4) 1112−(25+x)=231112−(25+x)=23
⇒25+x=1112−23=14⇒25+x=1112−23=14
⇒x=14−25=−320⇒x=14−25=−320
5) 234.x=317:0,01234.x=317:0,01
⇒114.x=117:1100=11007⇒114.x=117:1100=11007
⇒x=11007.411=447⇒x=11007.411=447
6) 2x.(x−17)=02x.(x−17)=0
⇒x−17=0⇒x−17=0 (1) hoặc x=0x=0
(1) ⇒x=17⇒x=17
Vậy x={0;17}x={0;17}
7) 34+14:x=2534+14:x=25
⇒14:x=25−34=−720⇒14:x=25−34=−720
⇒x=14:−720=14.−207=−57⇒x=14:−720=14.−207=−57
8) 3,8:2x=14:2233,8:2x=14:223
⇒1,9x=14:83=14.38=332⇒1,9x=14:83=14.38=332
⇒x=332:1,9=15304⇒x=332:1,9=15304
9) 0,25x:3=56:0,125=56:18=56.8=2030,25x:3=56:0,125=56:18=56.8=203
⇒0,25x=203.3=20⇒0,25x=203.3=20
⇒x=20:0,25=80⇒x=20:0,25=80
10) 113:0,8=23:0,1x113:0,8=23:0,1x
⇒43:45=23:110.x⇒43:45=23:110.x
⇒53=203.x⇒53=203.x
⇒x=53:203=14⇒x=53:203=14
11) 3,2x+(−1,2)x+2,7=−4,93,2x+(−1,2)x+2,7=−4,9
⇒2x+2,7=−4,9⇒2x+2,7=−4,9
⇒2x=−4,9−2,7=−7,6⇒2x=−4,9−2,7=−7,6
⇒x=−3,8⇒x=−3,8
12) |x|−2,2=1,3|x|−2,2=1,3
⇒|x|=1,3+2,2=3,5⇒|x|=1,3+2,2=3,5
⇒x=±3,5⇒x=±3,5
13) |x+34|−13=0|x+34|−13=0
⇒|x+34|=13⇒|x+34|=13
⇒x+34=13⇒x=−512⇒x+34=13⇒x=−512
hoặc x+34=−13⇒x=−1312x+34=−13⇒x=−1312
Vậy x={−512;−1312}x={−512;−1312}
14) |x+13|−4=−1|x+13|−4=−1
⇒|x+13|=−1+4=3⇒|x+13|=−1+4=3
⇒x+13=3⇒x=83⇒x+13=3⇒x=83
Hoặc x+13=−3⇒x=−3−13=−103x+13=−3⇒x=−3−13=−103
15) Do |x−1,5|≥0|x−1,5|≥0 và |2,5−x|≥0|2,5−x|≥0 với mọi giá trị của xx
⇒|x−1,5|+|2,5−x|=0⇒|x−1,5|+|2,5−x|=0 khi
⇒x−1,5=0⇒x=1,5⇒x−1,5=0⇒x=1,5 và 2,5−x=0⇒x=2,52,5−x=0⇒x=2,5 (loại vì ra 2 kết quả khác nhau)