Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1)
a) 2x + 5 = 3⁴ : 3²
2x + 5 = 3²
2x + 5 = 9
2x = 9 - 5
2x = 4
x = 4 : 2
x = 2
b) (3x - 24).73 = 2.74
(3x - 24).73 = 148
3x - 24 = 148/73
3x = 148/73 + 24
3x = 1900/73
x = 1900/73 : 3
x = 1900/219
c) [3.(42 - x)] + 15 = 23.3
126 - 3x + 15 = 69
141 - 3x = 69
3x = 141 - 69
3x = 72
x = 72 : 3
x = 24
d) 126 + (132 - x) = 300
132 - x = 300 - 126
132 - x = 174
x = 132 - 174
x = -42
2)
a) 120 - (x + 55) = 60
x + 55 = 120 - 60
x + 155 = 60
x = 60 - 55
x = 5
b) (7x - 11).3 = 25.52 + 200
(7x - 11).3 = 1500
7x - 11 = 1500 : 3
7x - 11 = 500
7x = 500 + 11
7x = 511
x = 511 : 7
x = 73
c) 2x + 2x + 4 = 544
4x = 544 - 4
4x = 540
x = 540 : 4
x = 135
Bài 1:
a) Ta có: \(x\left(x^2-4\right)=0\)
\(\Leftrightarrow x\left(x-2\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-2=0\\x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-2\end{matrix}\right.\)
Vậy: \(x\in\left\{0;2;-2\right\}\)
b) Ta có: \(\left(2x-3\right)+\left(-3x\right)-\left(x-5\right)=40\)
\(\Leftrightarrow2x-3-3x-x+5=40\)
\(\Leftrightarrow-2x+2=40\)
\(\Leftrightarrow-2x=38\)
hay x=-19
Vậy: x=-19
Bài 2:
a) Ta có: \(-45\cdot12+34\cdot\left(-45\right)-45\cdot54\)
\(=-45\cdot\left(12+34+54\right)\)
\(=-45\cdot100\)
\(=-4500\)
b) Ta có: \(43\cdot\left(57-33\right)+33\cdot\left(43-57\right)\)
\(=43\cdot57-43\cdot33+43\cdot33-33\cdot57\)
\(=43\cdot57-33\cdot57\)
\(=57\cdot\left(43-33\right)\)
\(=57\cdot10=570\)
a: \(\Leftrightarrow x+33=45\)
hay x=12
b: \(\Leftrightarrow x+73=102\)
hay x=29
c: \(\Leftrightarrow x+9=39\)
hay x=30
`@` `\text {Ans}`
`\downarrow`
`a)`
`2 \times x + 34 = 168`
`=> 2x = 168 - 34`
`=> 2x = 134`
`=> x = 134 \div 2`
`=> x = 67`
Vậy, `x=67`
`b)`
`x \times 11 + 51 = 273`
`=> 11x = 273 - 51`
`=> 11x = 222`
`=> x = 222 \div 11`
`=> x = 222/11`
`c)`
`x \div 120 - 45 = 155`
`=> x \div 120 = 155 + 45`
`=> x \div 120 = 200`
`=> x = 200 \times 120`
`=> x = 24000`
Vậy, `x = 24000`
`d)`
`320 \div x - 127 = 33`
`=> 320 \div x = 33+127`
`=> 320 \div x = 160`
`=> x = 320 \div 160`
`=> x = 2`
Vậy, `x=2.`
`@` `\text {Kaizuu lv uuu}`
a)2 x x +34 =168
2 x X = 168 - 34
2 x X = 134
X= 134:2
X= 67
b) x x 11 + 51 = 273
X x 11 = 273 - 51
X x 11= 222
X= 222 :11
X= 222/11
c) x : 120 – 45 = 155
x:120= 155+45
x:120=200
x=200:120
x=5/3
d) 320 : x – 127 = 33
320: x= 33+127
320:x=160
x=320:160
x=2