3/4+2/5x=29/60
Bài 1:
a. Tính:
1+22+23+....+29+210
b. Tìm x biết:
a] 60 - 3 . [x-1] = 23. 3
b] [3x - 2]3 = 2 . 25
c] 5x+1 - 5x = 500
d] x2 = x4
a) Đặt: \(A=1+2^2+2^3+...+2^{10}\)
\(\Rightarrow2A=2\left(1+2^2+2^3+...+2^9+2^{10}\right)\)
\(\Rightarrow2A=2+2^3+2^4+...+2^{10}+2^{11}\)
\(\Rightarrow2A-A=\left(2+2^3+2^4+...+2^{10}+2^{11}\right)-\left(1+2^2+2^3+...+2^{10}\right)\)
\(\Rightarrow A=\left(2^3-2^3\right)+\left(2^4-2^4\right)+...+\left(2-1\right)+\left(2^{11}-2^2\right)\)
\(\Rightarrow A=0+0+...+1+\left(2^{11}-2^2\right)\)
\(\Rightarrow A=1+2^{11}-2^2=1+2048-4=2045\)
Vậy: \(1+2^2+2^3+...+2^{10}=2045\)
b)
a] \(60-3\left(x-1\right)=2^3\cdot3\)
\(\Rightarrow60-3\left(x-1\right)=24\)
\(\Rightarrow3\left(x-1\right)=36\)
\(\Rightarrow x-1=12\)
\(\Rightarrow x=13\)
b] \(\left(3x-2\right)^3=2\cdot2^5\)
\(\Rightarrow\left(3x-2\right)^3=2^6\)
\(\Rightarrow\left(3x-2\right)^3=\left(2^2\right)^3\)
\(\Rightarrow3x-2=2^2\)
\(\Rightarrow3x=6\)
\(x=2\)
c] \(5^{x+1}-5^x=500\)
\(\Rightarrow5^x\left(5-1\right)=500\)
\(\Rightarrow5^x\cdot4=500\)
\(\Rightarrow5^x=125\)
\(\Rightarrow5^x=5^3\)
\(\Rightarrow x=3\)
d] \(x^2=x^4\)
\(\Rightarrow x=x^2\)
\(\Rightarrow x-x^2=0\)
\(\Rightarrow x\left(1-x\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\1-x=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
A.3/4+2/5x=29/60
B.x mũ 4=16
C.(x+5) mũ 3=-64
D.(x-3/4) mũ 2=0
E.x:8,5=0,69 : (-1,15)
Hộ bé vs ạ😘 thanks
a) \(\frac{3}{4}+\frac{2}{5}x=\frac{29}{60}\)
\(\frac{2}{5}x=\frac{29}{60}-\frac{3}{4}\)
\(\frac{2}{5}x=\frac{-4}{15}\)
\(x=\frac{-4}{15}:\frac{2}{5}\)
\(x=\frac{-2}{3}\)
b) \(x^4=16\)
\(x^4=2^4\)
\(x=2\)
c) \(\left(x+5\right)^3=-64\)
\(\left(x+5\right)^3=-4^3\)
\(x+5=-4\)
\(x=-4-5\)
\(x=-9\)
d) \(\left(x-\frac{3}{4}\right)^2=0\)
\(\left(x-\frac{3}{4}\right)^2=0^2\)
\(x-\frac{3}{4}=0\)
\(x=0+\frac{3}{4}\)
\(x=\frac{3}{4}\)
e) \(x:8,5=0,69:\left(-1,15\right)\)
\(x:8,5=-0,6\)
\(x=-0,6.8,5\)
\(x=-5,1\)
A.2/5x=29/60-3/4
2/5x=29/60-45/60
2/5x=-4/15
x=-4/15:2/5
x=4/15.5/2
x=-2/3
B. x mũ 4 = 42
-) x=2
C. (x+5) mũ 3 = -4 3
x+5 = -4
X= -4-5
X=-9
D. ( X -3/4)mũ 2=0 mũ 2
X= 0+3/4
X=3/4
E. X:8,5=-0,6
X=-0,6*8,5
X=5,1
Tìm x biết 3/4+2/5x=29/60
mn tính giúp mifh với, nêu rõ các bước tính luôn hen!
Bài 1: thực hiện phép tính
a) 3/4 . 44 1/5 -3/4 . 28 1/5
b) (-9,43 . 25) . 0,4
c) (-3)2 +V16/25 - V19 +V81/3
Bài 2 Tính
a) x : -7/5= 29/60
b)3/4+ 2/5x = 29/60
Câu 4.
a) Tìm x biết : x/3 = 9/4 và xy= 300
b) So sánh : 2300 và 3200
Bài 2:
a: \(\Leftrightarrow x=\dfrac{29}{60}\cdot\dfrac{-7}{5}=\dfrac{-203}{300}\)
b: \(\Leftrightarrow x\cdot\dfrac{2}{5}=\dfrac{29}{60}-\dfrac{3}{4}=\dfrac{29-45}{60}=\dfrac{-16}{60}=\dfrac{-8}{30}\)
\(\Leftrightarrow x=\dfrac{-8}{30}:\dfrac{2}{5}=\dfrac{-8\cdot5}{30\cdot2}=\dfrac{-40}{60}=-\dfrac{2}{3}\)
1.tìm x biết
a,15-(3+x)+2x=19
b,(-58)-(19-58-x)=60
c,2(x-4)-3(x+5)=4
d,(2-3x)+(x-3)=(5x-1)-(5x-2)
2.Tính nhanh
a,A= -3752-(29-3632)-51
b,B=3542-(674-798)-(326+2798)
1. a, 15-(3+x)+2x=19
=> 15- 3 - x + 2x = 19
=> -x + 2x = 19 - 15 +3
=> ( -1 + 2 )x = 7
=> x = 7
b, (-58)-(19-58-x)=60
=> (-58)-(-39-x)=60
=> -58 +39 + x = 60
=> -19 + x = 60
=> x = 60 - (-19) = 79
c, 2(x-4)-3(x+5)=4
=> (2x - 8 )-(3x+15)= 4
=> 2x - 8 - 3x - 15 = 4
=> 2x - 3x = 4 + 15 + 8
=> - x = 27
=> x = -27
d, (2-3x)+(x-3)=(5x-1)-(5x-2)
=> 2 - 3x + x - 3 = 5x - 1 - 5x + 2
=> 2 - 3 - 3x + x = 5x - 5x - 1 +2
=> 2 - 3 - 3x + x = 1
=> - 3x + x = 1 - 2 + 3
=> -2x = 2
=> x= -1
=))))
2.
a,
A= -3752-(29-3632)-51
A= -3572-29+3632-51
A=(-3572+3632)-29-51
A=
1> a, 15 - ( 3 + x ) + 2 x = 19
=> 15 - 3 - x + 2x = 19
=> -x + 2x = 19 - 15 +3
=> ( -1 + 2 ) x = 7
=> x = 7
b, ( -58 ) - ( 19-58-x ) = 60
=> ( -58 ) - ( -39 – x ) = 60
=> -58 + 39 + x = 60
=> -19 + x = 60
=> x = 60 - ( -19 ) = 79
c, 2 ( x - 4 ) - 3 ( x+5 ) = 4
=> ( 2x - 8 ) - ( 3x + 15 ) = 4
=> 2x - 8 - 3x - 15 = 4
=> 2x - 3x = 4 + 15 + 8
=> - x = 27
=> x = -27
d, ( 2 - 3x ) + ( x - 3 ) = ( 5x - 1 ) - ( 5x – 2 )
=> 2 - 3x + x - 3 = 5x - 1 - 5x + 2
=> 2 - 3 - 3x + x = 5x - 5x - 1 +2
=> 2 - 3 - 3x + x = 1
=> - 3x + x = 1 - 2 + 3
=> -2x = 2
=> x= -1
Tìm x biết
a,x+1/4=3/4
b,3/4-2/5x=29/60
c,11/12-2/3|x|=3/8
e,2x.1/3=-5/6
f,2-x÷3/4=1/2
Các bn ơi giúp mk với chiều mk đi học rồi!!!!!!
(2+2/3-1/4)x1/5
A.13/60 B.1/15 C. 3/60 D.29/60
( 5x – 29 ) – ( 2x – 29 ) = - 21
3.( 2 – x ) + 4.( x – 5 ) = 14
( 2x – 1)2– 29 = - 4
x^2+ 5 = 14
giups mik vois
\(\left(5x-29\right)-\left(2x-29\right)=-21\)
\(5x-29-2x+29=-21\)
\(5x-2x=-21+29-29\)
\(3x=-21\)
\(x=-7\)
kết quả của phép tính :
(2+2/3 - 1/4 ) x 1/5
A 13/60 B 1/15 C 29/60 D 3/60