a x 5 + a x 4 + a x 3 = 54
bài 1 tìm x biết
a:34+3x=130
b 54-4(5+x)=10
c 42022 . (5x-4) =42024
2 .(x+1)3= 54
bài 2 cho A= 5+52+53+...+52022.tìm x để 4A+5=5x
bài 3 cho A=4+42+43+...+42023+42024
a tính giá trị của biểu thức A
b biểu thức A có chia hết cho 20 ko?vì sao?
bài 4 cho biểu thức A=2+22+23+...+2100
a A có chia hết cho 6 ko ? vì sao?
b A có chia hết cho 7 ko ? vì sao?
giúp mình với mình đang cần gấp
bài 1 có ý d nha các bạn mình viết thiếu
a)/x/-/\(\dfrac{-3}{4}\)/=/\(\dfrac{2}{5}\)/
b)/x+\(\dfrac{1}{3}\)/=/\(\dfrac{-2}{9}\)/
c)3\(^x\)*5+3\(^x\)=54
\(a,\Leftrightarrow\left|x\right|=\dfrac{2}{5}+\dfrac{3}{4}=\dfrac{23}{20}\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{23}{20}\\x=-\dfrac{23}{20}\end{matrix}\right.\\ b,\Leftrightarrow\left|x+\dfrac{1}{3}\right|=\dfrac{2}{9}\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{3}=\dfrac{2}{9}\\x+\dfrac{1}{3}=-\dfrac{2}{9}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{9}\\x=-\dfrac{5}{9}\end{matrix}\right.\\ c,\Leftrightarrow3^x\cdot6=54\Leftrightarrow3^x=9=3^2\Leftrightarrow x=2\)
a. x - 285 : 35 = 5 x 54 b. ( x + 120 ) : 20 =8 c . ( x + 5 ) x 3 = 300 d. ( x + 100 ) x 4 = 800
a) \(x-285\div35=5\times54\)
\(x-\dfrac{57}{7}=270\)
\(x=\dfrac{1947}{7}\)
b) \(\left(x+120\right)\div20=8\)
\(x+120=160\)
\(x=40\)
c) \(\left(x+5\right)\times3=300\)
\(x+5=100\)
\(x=95\)
d) \(\left(x+100\right)\times4=800\)
\(x+100=200\)
\(x=100\)
a) \(x-285:35=5x54\)
\(x-\dfrac{57}{7}=270\)
\(x=270+\dfrac{57}{7}=\dfrac{1890}{7}+\dfrac{57}{7}=\dfrac{1947}{7}\)
b) \(\left(x+20\right):20=8\)
\(\left(x+20\right)=8x20\)
\(x+20=160\)
\(x=160-20=140\)
c) \(\left(x+5\right)x3=300\)
\(x+5=300:3\)
\(x+5=100\)
\(x=100-5=95\)
d) \(\left(x+100\right)x4=800\)
\(x+100=800:4\)
\(x+100=200\)
\(x=200-100=100\)
a) ( 5.x - 1 ) : 3 + 1 = 4
b) 54 : ( 16 - x ) - 1 = 5
c) 3^2 . x + 15 = 60
d) 2x^3 = 54
e) 2^x+1 = 64
a ) x = 2
b ) x = 7
c ) x = 5
d ) đề sai ......! hoặc x = rỗng .
e ) x = 5
1) CMR: 543-54 khong la so chinh phuong
2) Tim x:
2(x-2).(x+3)-x2+4=0
3) Rut gon
a)2(x+1)2-3(x-1)2+(x+2).(5-x)
b)(3x-1)3+(3x-1)3-6x2+9
4) A= (x-5).(x+2)+3.(x-2).(x+2)-(3x-1)2+5x2
a) rut gon A
b) tinh a khi x =1/2
Tìm số nguyên x, biết:
a) 3 − 5 = x + 5 10
b) x − 4 6 = 1 − 3
c) 3 5 = − 9 3 x
d) 5 7 = 2 x 14
e) 5 − x 2 = 2 5 − x
f) 4 − x − 5 = − 5 4 − x
a) x = -11
b) x = 2
c) x = -5
d) x = 5
e) x = 3 hoặc x = 7
f) x = -1 hoặc x = 9
a ) - 7 -15 + 30
b )10 x 23 - 10 x (-17)c )21 x 3 -7 x[(-32) + 18]d )-20 - [ 10 x (4 mũ 3 - 54) x 5 mũ 2 + 2 mũ 4]a: =30-22=8
b: =10*(23+17)=10*40=400
c: =21*3-7*(-14)
=63+98=161
d: =-20-[10*10*5^2+16]
=-20-100*25-16
=-36-2500
=-2536
A = 4 mũ 10 x 8 mũ 15 b = 4 mũ 15 x 5 mũ 30 C = 27 mũ 16 chia 9 mũ 10 b = a = 72 mũ 3 x 54 mũ 2 chia cho 158 mũ 4 b = 3 mũ 10 x 11 + 3 mũ 10 x 5 chia 3 mũ 9 x 24
mình cũng hỏi về cái này gấp nha ai biết trả lời câu nào thì trả
1)tìm x
a)(1/3-5/6.x)^3+21/54=5/6
b)1/12-1/3(1/2.x-1)^4=1/16
c)(3/5)^x-1+5.(3/5)^x-1=54/25
d)(2/3)^x+(2/3)^x+2=101/243
2) so sánh
a)1/27^11 và 1/81^8
b)1/3^99 và 1/11^21
a) => \(\left(\frac{1}{3}-\frac{5}{6}x\right)^3=\frac{5}{6}-\frac{21}{54}=\frac{24}{54}=\frac{4}{9}\)
=> \(\frac{1}{3}-\frac{5}{6}x=\sqrt[3]{\frac{4}{9}}\) => \(\frac{5}{6}x=\frac{1}{3}-\sqrt[3]{\frac{4}{9}}\) => \(x=\frac{6}{5}.\left(\frac{1}{3}-\sqrt[3]{\frac{4}{9}}\right)\)
b) \(\frac{1}{3}\left(\frac{1}{2}x-1\right)^4=\frac{1}{12}-\frac{1}{16}=\frac{1}{48}\) => \(\left(\frac{1}{2}x-1\right)^4=\frac{3}{48}=\frac{1}{16}\)
=> \(\frac{1}{2}x-1=\frac{1}{2}\) hoặc \(\frac{1}{2}x-1=-\frac{1}{2}\)
=> \(\frac{1}{2}x=\frac{3}{2}\) hoặc \(\frac{1}{2}x=\frac{1}{2}\) => x = 3 hoặc x = 1
c) \(\left(1+5\right).\left(\frac{3}{5}\right)^{x-1}=\frac{54}{25}\) => \(\left(\frac{3}{5}\right)^{x-1}=\frac{9}{25}=\left(\frac{3}{5}\right)^2\)
=> x - 1= 2 => x = 3
d) \(\left(1+\left(\frac{2}{3}\right)^2\right).\left(\frac{2}{3}\right)^x=\frac{101}{243}\) => \(\frac{13}{9}.\left(\frac{2}{3}\right)^x=\frac{101}{243}\)
=> \(\left(\frac{2}{3}\right)^x=\frac{101}{243}:\frac{13}{9}=\frac{101}{351}\) (có lẽ đề sai)
2) \(\frac{1}{27^{11}}=\frac{1}{\left(3^3\right)^{11}}=\frac{1}{3^{33}}\); \(\frac{1}{81^8}=\frac{1}{\left(3^4\right)^8}=\frac{1}{3^{32}}\)
Vì 333 > 332 => \(\frac{1}{3^{33}}\) < \(\frac{1}{3^{32}}\) => \(\frac{1}{27^{11}}\) < \(\frac{1}{81^8}\)
b) \(\frac{1}{3^{99}}=\frac{1}{\left(3^3\right)^{33}}=\frac{1}{27^{33}}