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a, \(\dfrac{5}{9}.\dfrac{10}{11}+\dfrac{5}{9}.\dfrac{14}{11}-\dfrac{5}{9}.\dfrac{15}{11}=\dfrac{5}{9}.\left(\dfrac{10}{11}+\dfrac{14}{11}-\dfrac{15}{11}\right)=\dfrac{5}{9}.\dfrac{9}{11}=\dfrac{5}{11}\)
b, \(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{3}{13}.\dfrac{6}{7}\)\(=\dfrac{6}{7}.\left(\dfrac{8}{13}-\dfrac{3}{13}\right)+\dfrac{6}{13}.\dfrac{9}{7}=\dfrac{6}{7}.\dfrac{5}{13}+\dfrac{54}{91}=\dfrac{30}{91}+\dfrac{54}{91}=\dfrac{84}{91}=\dfrac{12}{13}\)
Bạn ơi, gõ latex cho dễ nhìn nhé!
a) x+30%x=-1.31
=> 100%x+30%x=-1.31
=>x.(100%+30%)=-1.31
=>x.13/10=-1.31=-1.31:13/10=-131/130
b) (x-1/2):1/3+5/7=9+5/7
=>(x-1/2).3+5/7=68/7
=>(x-1/2).3=68/7-5/7=9
=>x-1/2=9:3=3
=>x=3+1/2=3 1/2( hỗn số)
c) 1/2x-3/4=14/9.3/7
=>1/2x-3/4=2/3
=>1/2x=2/3+3/4=17/12
x=17/12:1/2=17/12.2=17/6
d) - 5/6 -x = 7/12+ -1/3
=>- 5/6 -x = 7/12+ -4/12=1/4
=> x = -5/6 -1/4=-13/12
e) x + 3/-15 = 1/3
=> x= 1/3 - -3/15 =1/3+3/15
=> x=5/15 + 3/15=8/15
f) (4,5 -2 x). (-1 4/7)=11/14
=> 4,5 -2x=11/14 : -3/7=11/14. -7/3=-11/6
=>-2x=-11/6-9/2= -11/6 -27/6 =-19/3
=>x= -19/3: -2x=19/6
Chúc bn thi HKII tốt!!!
\(\left(x+2\right)-2=0\)
\(\Rightarrow x+2-2=0\)
\(\Rightarrow x=0\)
\(\left(x+3\right)+1=7\)
\(\Rightarrow x+3+1=7\)
\(\Rightarrow x+4=7\)
\(\Rightarrow x=3\)
\(\left(3x-4\right)+4=12\)
\(\Rightarrow3x-4+4=12\)
\(\Rightarrow3x=12\)
\(\Rightarrow x=4\)
\(\left(5x+4\right)-1=13\)
\(\Rightarrow5x+4-1=13\)
\(\Rightarrow5x+3=13\)
\(\Rightarrow5x=10\)
\(\Rightarrow x=2\)
\(\left(4x-8\right)-3=5\)
\(\Rightarrow4x-8-3=5\)
\(\Rightarrow4x-11=5\)
\(\Rightarrow4x=16\)
\(\Rightarrow x=4\)
\(8-\left(2x+4\right)=2\)
\(\Rightarrow8-2x-4=2\)
\(\Rightarrow4-2x=2\)
\(\Rightarrow2x=2\)
\(\Rightarrow x=1\)
\(7+\left(5x+2\right)=14\)
\(\Rightarrow7+5x+2=14\)
\(\Rightarrow9+5x=14\)
\(\Rightarrow5x=5\)
\(\Rightarrow x=1\)
\(5-\left(3x-11\right)=1\)
\(\Rightarrow5-3x+11=1\)
\(\Rightarrow16-3x=1\)
\(\Rightarrow3x=15\)
\(\Rightarrow x=5\)
a, 8^5=8192;3.4^7=3.16384=49152
=>8^5<3.4^7
b,cái nè dài quá nên chị viết ngắn gọn thôi ha!^.^
31^11>17^14
c,5^333<3^555
a) x + 30%x = -1,31
(1 + 30%)x = -1,31
13/10x = -1,31
x = -1,31 : 13/10
x = -131/130
b) (x - 1/2) : 1/33 + 5/7 = 68/7
(x - 1/2) : 1/33 = 68/7 - 5/7
(x - 1/2) : 1/33 = 9
(x - 1/2) = 9 x 1/33
x - 1/2 = 3/11
x = 3/11 + 1/2
x = 17/22
c) (4,5 - 2x) . ( -11) = 11/14
(4,5 - 2x) = 11/14 : (-11)
(4,5 - 2x) = -1/14
2x = 4,5 + 1/14
2x = 32/7
x = 16/7
a,x + 30%x = -1,31
x.130%= -1,31
x = -131/130
b, (x-1/2) : 1/33 + 5/7 = 68/7
(x-1/2) . 33 = 68/7 -5/7
(x-1/2).33 = 9
x-1/2 = 9:33
x-1/2 = 3/11
x = 3/11 + 1/2
x =17/22
c,(4,5 - 2x).(-11) = 11/14
4,5 - 2x = 11/14 : (-11)
4,5 - 2x = -1/14
2x = 4,5 -(-1/14)
2x = 32/7
\(2x\cdot\dfrac{-4}{9}+2x\cdot\dfrac{-5}{9}=\dfrac{8}{11}\)
\(2x\cdot\left(\dfrac{-4}{9}+\dfrac{-5}{9}\right)=\dfrac{8}{11}\)
\(2x\cdot\left(-1\right)=\dfrac{8}{11}\)
2x = \(\dfrac{8}{11}:\left(-1\right)=\dfrac{-8}{11}\)
x = \(\dfrac{-8}{11}:2=\dfrac{-4}{11}\)
Rút gọn các biểu thức sau:
a) -11 +y+7
b) x+22+(-14)
c) a+(-15)+62
Nhớ giúp mk nhé , có cách giải đó nha
a, -11 +y+7
=(-11)+7+y
=(-4)+y
b, x+22+(-14)
=x+8
c, a+(-15)+62
=a+47
tick nha lợn ka ka
a)\(\left(x+8\right)-11=20-15\)
\(\left(x+8\right)-11=5\)
\( x+8=5+11\)
\(x+8=16\)
\(x=8\)
b) \(2x-\left(3+x\right)=5-7\)
\(2x-\left(3+x\right)=-2\)
\(2x-3-x=-2\)
\(x=1\)
c) \( \left(3x-2^4\right)\times7^5=2\times7^6\)
\(3x-2^4=2\times\left(7^6:7^5\right) \)
\(\left(3x-2^4\right)=2\times7^2\)
\(3x-2^4=2\times49\)
\(3x-16=98\)
\(3x=114\)
\(x=38\)
Câu 1: 2x + 14 = 38 => 2x = 38 - 14 = 24 => x = 24 : 2 = 12. Câu 2: 210 : (x - 11) = 7 => x - 11 = 210 : 7 = 30 => x = 30 + 11 = 41. Hok tốt