125 : (2x - 3x) = 55 : 53
Tìm x biết:
\(a,18:(x-3)=6\)
\(b,\)\(3^{x-1}+4=85\)
\(c,2x+3x=55\)
\(\left(x-3\right)^3+11=53\)
a: 18:(x-3)=6
=>x-3=18:6=3
=>x=3+3=6
b: \(3^{x-1}+4=85\)
=>\(3^{x-1}=81\)
=>\(3^{x-1}=3^4\)
=>x-1=4
=>x=5
c: 2x+3x=55
=>5x=55
=>x=55/5=11
d: \(\left(x-3\right)^3+11=53\)
=>\(\left(x-3\right)^3=53-11=42\)
=>\(x-3=\sqrt[3]{42}\)
=>\(x=\sqrt[3]{42}+3\)
a) 18 : (x - 3) = 6
x - 3 = 18 : 6
x - 3 = 3
x = 3 + 3
x = 6
b) 3ˣ⁻¹ + 4 = 85
3ˣ⁻¹ = 85 - 4
3ˣ⁻¹ = 81
3ˣ⁻¹ = 3⁴
x - 1 = 4
x = 4 + 1
x = 5
c) 2x + 3x = 55
5x = 55
x = 55 : 5
x = 11
d) Sửa đề:
(x - 3)³ - 11 = 53
(x - 3)³ = 53 + 11
(x - 3)³ = 64
(x - 3)³ = 4³
x - 3 = 4
x = 4 + 3
x = 7
TTìm số nguyên x, biết: a) 262 + ( 2x - 123)= 283; b) 63 - ( - 51 + 3x) = 237 c) - ( 2x + 24) + 211 = -123 d) 125 - ( 125 - x) + 22+ 3x) = 237 c) - ( 2x + 24) + 211 = -123 d) 125 - ( 125 - x) + 22
Tìm x, biết :
a, 2x - (-3x - 17) = 53 - 26 - x
b,5x - (-24) =33-78+4x
c,(7x - 19) - (5x -12) = 3x - (9-2x) -1
d,(2x +5)2 = -125
e,(4x - 3)2 = 289
f,-2*(12-5x)3 = -686
g,2mũ x+5 -3*2mũ x = 928
h,3mũ x +3 mũ x+1 + 3mũ x+2 = 13
Bài 5: Giải các phương trình sau :
a) \(\frac{3x-1-\frac{x-1}{2}}{3}-\frac{2x+\frac{1-2x}{3}}{2}=\frac{\frac{3x-1}{2}-6}{5}\)
b) \(\frac{x-23}{24}+\frac{x-23}{25}=\frac{x-23}{26}+\frac{x-23}{27}\)
c) \(\frac{x+1}{2004}+\frac{x+2}{2003}=\frac{x+3}{2002}+\frac{x+4}{2001}\)
d) \(\frac{x-45}{55}+\frac{x-47}{53}=\frac{x-55}{45}+\frac{x-53}{47}\)
e) \(\frac{x+2}{98}+\frac{x+4}{96}=\frac{x+6}{94}+\frac{x+8}{92}\)
Giải phương trình: 3 x + 2 2 - 3 x + 1 6 = 2 x + 5 3
⇔ 3(3x + 2) – (3x + 1) = 12x + 10
⇔ 9x + 6 – 3x – 1 = 12x + 10
⇔ 6x + 5 = 12x + 10
⇔ 6x – 12x = 10 – 5
⇔ -6x = 5
⇔
Vậy phương trình có tập nghiệm
a) -2x - (-17)= 9 b) 11 + (15 – x) = 1
c) 53 – 7x = 57 : 55 | d) 29 +9.x2 = 110 |
e) (2x-4).(3-x) = 0
g) 2x + 1 chia hết cho x -2 |
a: =>-2x=9-17=-8
hay x=4
b: =>15-x=-10
hay x=25
d: \(\Leftrightarrow9x^2=81\)
hay \(x\in\left\{3;-3\right\}\)
e: \(\Leftrightarrow\left[{}\begin{matrix}2x-4=0\\3-x=0\end{matrix}\right.\Leftrightarrow x\in\left\{2;3\right\}\)
Bài 2: (2,5 điểm) Tìm x, biết:
a) 23 + 3x = 125 b) 70 – 5.(x - 3)= 45 c) 20 + 5x = 57:55
a)23+3 𝑥 =125 | b) 70 – 5.(𝑥 - 3)= 45 | c) 20 + 5 𝑥 = 57:55
3 𝑥 +23=125 | 70−5 𝑥 +15=45 | 5 𝑥 +20=5755
𝑥=34 | 𝑥=8 | 𝑥=−104
275
a: \(\Leftrightarrow3x=102\)
hay x=34
Tính hợp lý nếu có thể
a)-17+55-(-25-17)
b) 53.(-15)+43.15-15.90
c)125.(-25).32.2018
d) (-1) mũ 2019.[ 5 mũ 3 - (-4) mũ 2] .2018 mũ 0
Tìm x ∈ N , biết.
a) 3 x + 1 : 3 4 = 81
b) 3 x + 3 . 3 x + 1 = 729
c) 2 x + 3 . 2 x = 128
d) 23 + 3 x = 5 6 : 5 3
e) 2 x + 2 x + 4 = 272