( 3x - 31)4 = 16
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Giúp mình với (rõ cách làm)(p.s không cần lảm hết đâu 1 câu cũng được)
2x-16=40+x
16-2x=40-3x
2(4x-2x)-7x=16
-2(-3-4x)-3(3x+7)=31
9(x+4)-4(2x+15)=3
-2[x+(-7)]+(x-3)=12
(x-7)(x+2005)=0
2x-16=40+x
2x-x=40+16
x=56
tick nhé cảm ơn
(x-7)(x+2005) = 0
\(\Rightarrow\) x-7 = 0
Vậy x = 7
Giúp mình với (gấp với ai đúng đều cho 5 sao)
2x-16=40+x
16-2x=40-3x
2(4x-2x)-7x=16
-2(-3-4x)-3(3x+7)=31
9(x+4)-4(2x+15)=3
-2[x+(-7)]+(x-3)=12
(x-7)(x+2005)=0
2x-16=40+x=>x=56
16-2x=40-3x=>x=24
2(4x-2x)-7x=16=>x=-5,(3)
-2(-3-4x)-3(3x+7)=31=>x=-46
9(x+4)-4(2x+15)=3=>x=27
-2[x+(-7)]+(x-3)=12=>x=-1
(x-7)(x+2005)=0 =>x=7;-2005
Gpt.
1,3√(3x+1)+10√(2-x)=13x-20√(-3x^2+5x+2)+9
2,(4x-1)√(x^2+16)=2x^2+2x+31
a) 3x+ (-5)= 23
b) I 1-x I +16 +31
c) 3x + 9 là bội của x+2
Tìm x thuộc Z biết
a) 2x-13=15
b) 31-3(1-x)=2x
c) /3x-7/=2
d) (x-1)^4=16
e) (-4)^x=64
g) x^3 = 4x =0
a) 2x-13=15
2x = 15+13
2x = 18
x = 18:2
x =9
c. /3x-7/=2
+) Nếu 3x-7=2 thì x = 3
+)Nếu 3x-7=-2 thì x = 5/3 không thuộc Z
Vậy x = 3
tính nhanh
25/37 x 18/29 + 18/29 x 12/37
31/85 x 11/19 + 31/85 x 12/19 - 42/19 x 31/85
c , 16/53 : 17/9 - 16/53 : 17/8
1/5 x 12/31 x 4/3 + 19/31 x 4/15
a) \(\dfrac{25}{37}\times\dfrac{18}{29}+\dfrac{18}{29}\times\dfrac{12}{37}\)
\(=\dfrac{18}{29}\times\left(\dfrac{25}{37}+\dfrac{12}{37}\right)\)
\(=\dfrac{18}{29}\times\dfrac{37}{37}\)
\(=\dfrac{18}{29}\times1\)
\(=\dfrac{18}{29}\)
b) \(\dfrac{31}{85}\times\dfrac{11}{19}+\dfrac{31}{85}\times\dfrac{12}{19}-\dfrac{42}{19}\times\dfrac{31}{85}\)
\(=\dfrac{31}{85}\times\left(\dfrac{11}{19}+\dfrac{12}{19}-\dfrac{42}{19}\right)\)
\(=\dfrac{31}{85}\times\dfrac{-19}{19}\)
\(=\dfrac{31}{85}\times-1\)
\(=-\dfrac{31}{85}\)
c) \(\dfrac{16}{53}:\dfrac{17}{9}-\dfrac{16}{53}:\dfrac{17}{8}\)
\(=\dfrac{16}{53}:\left(\dfrac{9}{17}-\dfrac{8}{17}\right)\)
\(=\dfrac{16}{53}:\dfrac{1}{17}\)
\(=\dfrac{16}{901}\)
c) \(\dfrac{1}{5}\times\dfrac{12}{31}\times\dfrac{4}{3}+\dfrac{19}{31}\times\dfrac{4}{15}\)
\(=\dfrac{4}{15}\times\dfrac{12}{31}+\dfrac{19}{31}\times\dfrac{4}{15}\)
\(=\dfrac{4}{15}\times\left(\dfrac{12}{31}+\dfrac{19}{31}\right)\)
\(=\dfrac{4}{15}\times\dfrac{31}{31}\)
\(=\dfrac{4}{15}\times1\)
\(=\dfrac{4}{15}\)
a: =18/29*(25/37+12/37)
=18/29
b: =31/85(11/19+12/19-42/19)
=-31/85
c; =16/53(9/17+8/17)=16/53
d: =4/15(12/31+19/31)=4/15
Bài 1: Thực hiện phép tính:
a/ (–4).(+125).( –25).( –8).( –6) b/ 65 – 5 ( 13 + 7)
c/ 24. ( 16 – 5) – 16. ( 24 – 5) d/ 18 . 35 – 7. 5 . 8
e/ 31 . (– 18) – 31. ( – 81) – 31
a, 6.(x-1)-5x=15
b, 2.(4x-2)-7x=16
c,-2.(-3-4x)-3.(3x-7)=31
a) => 6x-6-5x=15
=> 6x-6+6-5x=15+6
=> 6x-5x=21
=> x=21
b) => 8x-4-7x=16
=> 8x-4+4-7x=16+4
=> 8x-7x=20
=> x=20
c) => 8-[-(2.4x)]-9x-21=31
=> 8-(-8x)-9x=31+21
=> 8-(-8x)-9x=52
=> (-8x)-9x=8-52
=> (-8x)+(-9x)=-44
=> -17x=-44
=> x=(-44):(-17)
=> x=
câu c chắc tớ làm sai
tính C= \(9.\left(\frac{13-\frac{13}{7}-\frac{13}{289}}{4-\frac{4}{7}-\frac{4}{289}}:\frac{39+\frac{39}{5}+\frac{39}{139}+\frac{39}{31}}{16+\frac{16}{5}+\frac{16}{139}+\frac{16}{31}}\right).\frac{158158}{164164}\)
tính hộ ợ
\(C=9\cdot\left(\frac{\frac{26299}{2023}-\frac{3757}{2023}-\frac{91}{2023}}{\frac{8092}{2023}-\frac{1156}{2023}-\frac{28}{2023}}\right):\left(\frac{\frac{840255}{21545}+\frac{168051}{21545}+\frac{6045}{21545}+\frac{27105}{21545}}{\frac{344720}{21545}+\frac{68944}{21545}+\frac{2480}{21545}+\frac{11120}{21545}}\right)\cdot\frac{158158}{164164}\)
\(C=9\cdot\left(\frac{\frac{22451}{2023}}{\frac{6908}{2023}}\div\frac{\frac{1041456}{21545}}{\frac{427264}{21545}}\right)\cdot\frac{158158}{164164}\)
\(C=9\cdot\left(\frac{13}{4}\div\frac{39}{16}\right)\cdot\frac{158158}{164164}\)
\(C=9\cdot\frac{4}{3}\cdot\frac{2\cdot79\cdot2\cdot79}{2\cdot82\cdot2\cdot82}=9\cdot\frac{4}{3}\cdot\frac{79}{82}\)
\(C=\frac{474}{41}\)