giúp mik với : (n x 1 - n / 6 ) x ( 6 + 240 + 4 + 150 )
cú t ccau oiii ét ô ét giải giúp t bài này zới
4,7 : 0,25 + 5,3 x 4
3x ( a - 2) +150 = 240
1/9 + a + 7/12 = 17/18
( 1/2 x 1/3 + 1/3 x 1/4 + 1/4 x 1/5 + 1/5 x 1/6 + 1/6 x 1/7 + 1/7 x 1/8 ) x a = 9/16
\(4,7\div0,25+5,3\times4\)
\(=18,8+21,2\)
\(=40\)
\(3\times\left(a-2\right)+150=240\)
\(3\times\left(a-2\right)=90\)
\(a-2=30\)
\(a=32\)
\(\dfrac{1}{9}+a+\dfrac{7}{12}=\dfrac{17}{18}\)
\(\dfrac{1}{9}+a=\dfrac{13}{36}\)
\(a=\dfrac{1}{4}\)
\(\left(\dfrac{1}{2}\times\dfrac{1}{3}+\dfrac{1}{3}\times\dfrac{1}{4}+\dfrac{1}{4}\times\dfrac{1}{5}+\dfrac{1}{5}\times\dfrac{1}{6}+\dfrac{1}{6}\times\dfrac{1}{7}+\dfrac{1}{7}\times\dfrac{1}{8}\right)\times a=\dfrac{9}{16}\)
\(\left(\dfrac{1}{2\times3}+\dfrac{1}{3\times4}+\dfrac{1}{4\times5}+\dfrac{1}{5\times6}+\dfrac{1}{6\times7}+\dfrac{1}{7\times8}\right)\times a=\dfrac{9}{16}\)
\(\left(\dfrac{1}{2}-\dfrac{1}{8}\right)\times a=\dfrac{9}{16}\)
\(\dfrac{3}{8}\times a=\dfrac{9}{16}\)
\(a=\dfrac{3}{2}\)
x€N,1000:[30+(2^x -6)]=3^2+4^2
Mn giúp mik với ạ~
1000 : [30 + (2x - 6)] = 32 + 42
1000 : [30 + (2x - 6)] = 9 + 16
1000 : [30 + (2x - 6)] = 25
30 + (2x - 6) = 1000 : 25
30 + (2x - 6) = 40
2x - 6 = 40 - 30
2x - 6 = 10
2x = 10 + 6
2x = 16
2x = 24
⇒ x = 4
tính nhanh
1 ) 240 x 15 - 80 x 6 x 3 - 60 x 4
2 ) 150 x 5 x 3 x 6 - 15 x 11
1)240x15-80x6x3-60x4
=240x15-80x3x6-240x1
=240x15-240x6-240x1
=240x(15-6-1)
=240x8
=1920
2)150x5x3x6-15x11
150x5x6x3-15x10-150x0,2
=150x5x6x3-150x1-150x0,2
=150x(5+6+3-1-0,2)
=150x12,8
=1980
Tìm x thuộc N biết
a)\(\frac{7}{x}\)= \(\frac{x}{28}\)
b) \(\frac{10+x }{17+x}\)= \(\frac{3}{4}\)
c) \(\frac{40+x}{17+x}\)= \(\frac{6}{7}\)
Giúp mik với nha
Mik cần gấp
b) <=> 4(10+x) = 3(17+x)
40+4x=51+3x
4x-3x=51-40
x=11
c) <=> 7.(40+x) = 6 .(17+x)
280+7x =102 + 6x
7x-6x=102-280
x=-178
a) 7/x=x/28
=)7*28=x*x
=)196=x^2
=)14^2=x^2
= )x=14
k cho mih di roi mih giai tiep cho nha
=>2/x(x+2)+2/(x+2)(x+4)+...+2/(x+6)(x+8)=8/105
=>1/x-1/x+2+1/x+2-1/x+4+...+1/x+6-1/x+8=8/105
=>\(\dfrac{1}{x}-\dfrac{1}{x+8}=\dfrac{8}{105}\)
=>x(x+8)=105
=>x^2+8x-105=0
=>(x+15)(x-7)=0
=>x=7 hoặc x=-15
Làm giúp mik bài này với ạ !!! Ai làm đc thì mik cảm ơn nhìu nhìu ạ
1,x/2=y/3=z/5 và zx = 90
2,x/2=y/3=z/5 và xyz = 240
3,x/5=y/6=z/7vaf 2x+3y-z=42
4,x/3=y/15=z/7 và 5x-y+z =28
(X mũ 2 -4)mũ 22=( x mũ 2 - 4)mũ 11
6×5 mũ 2x +1 = 18750
132 mũ 456= 10k+x;(k,n thuộc N;0<x<10)
8 mũ 2 mũ 1999=...x (0<x<10)
ìm x giúp mink với ạ mik sắp phải nộp bài rồi
( x - 4/7) : -1/3 = 1
2/3 + 7/4 : x = 5/6
giúp mik với
\(\left(x-\dfrac{4}{7}\right):-\dfrac{1}{3}=1\)
\(\Rightarrow x-\dfrac{4}{7}=1\cdot-\dfrac{1}{3}\)
\(\Rightarrow x-\dfrac{4}{7}=-\dfrac{1}{3}\)
\(\Rightarrow x=-\dfrac{1}{3}+\dfrac{4}{7}\)
\(\Rightarrow x=\dfrac{5}{12}\)
___________________
\(\dfrac{2}{3}-\dfrac{7}{4}:x=\dfrac{5}{6}\)
\(\Rightarrow\dfrac{7}{4}:x=\dfrac{2}{3}-\dfrac{5}{6}\)
\(\Rightarrow\dfrac{7}{4}:x=-\dfrac{1}{6}\)
\(\Rightarrow x=\dfrac{7}{4}:-\dfrac{1}{6}\)
\(\Rightarrow x=-\dfrac{21}{2}\)
(x - 4/7) : (-1/3) = 1
x - 4/7 = -1/3
x = -1/3 +4/7
x = 5/21
--------------------
2/3 + 7/4 : x = 5/6
7/4 : x = 5/6 - 2/3
7/4 : x = 1/6
x = 7/4 : 1/6
x = 21/2
a) ( x - 4/7) : (-1/3) = 1
x- 4/7 = 1 . (-1/3)
x =-1/3 + 4/7
x = 5/12
b) 2/3 + 7/4 : x = 5/6
7/4: x = 2/3 -5/6
x = 7/4 : (-1/6 )
x = -21/2
a, tính (-24). 17.(-3)0.(-5)6.(-12n) (n thuộc N)
b, tìm x thuộc số nguyên
3./2x2-7/=33
Giúp mik với, mik cần gấp, ai nhanh mik tick
a.
(-2)4.17.(-3)0.(-5)6.(-12n)
=16.17.1.15625.-1
=(16.15625).[1.(-1)].17
=250000.(-1).17
=4250000
b.3(2x2-7)=33
2x2-7 =33:3
2x2-7 =11
2x2 =11+7
2x2 =18
x2 =18:2
x2 =9
x2 =\(\left(\pm3^2\right)\)
\(\Rightarrow\) TH1: x2 =32 TH2: x2 =(-3)2
\(\Rightarrow\) x =3 \(\Rightarrow\)x =-3
Vậy x\(\in\left\{3;-3\right\}\)