Tìm x :
a) x + 17 = 5
b) x - 34 = -6
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
NT
1
15 tháng 8 2021
a: Ta có: \(10-\left\{\left[\left(x:3+17\right):10+3\cdot2^4\right]:10\right\}=5\)
\(\Leftrightarrow\left[\left(x:3+17\right):10+48\right]:10=5\)
\(\Leftrightarrow\left(x:3+17\right):10+48=50\)
\(\Leftrightarrow\left(x:3+17\right):10=2\)
\(\Leftrightarrow x:3+17=20\)
\(\Leftrightarrow x:3=3\)
hay x=9
b: Ta có: \(2448:\left[119-\left(x-6\right)\right]=24\)
\(\Leftrightarrow119-\left(x-6\right)=102\)
\(\Leftrightarrow x-6=17\)
hay x=23
c: Ta có: \(165-\left(35:x+3\right)\cdot19=13\)
\(\Leftrightarrow\left(35:x+3\right)\cdot19=152\)
\(\Leftrightarrow\left(35:x+3\right)=8\)
\(\Leftrightarrow35:x=5\)
hay x=7
31 tháng 3 2021
Bài 1:
a) Ta có: \(\dfrac{2}{5}\cdot x+\dfrac{1}{3}=\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{2}{5}\cdot x=\dfrac{1}{5}-\dfrac{1}{3}=\dfrac{-2}{15}\)
\(\Leftrightarrow x=\dfrac{-2}{15}:\dfrac{2}{5}=\dfrac{-2}{15}\cdot\dfrac{5}{2}\)
hay \(x=-\dfrac{1}{3}\)
Vậy: \(x=-\dfrac{1}{3}\)
b) Ta có: \(\dfrac{1}{5}+\dfrac{5}{3}:x=\dfrac{1}{2}\)
\(\Leftrightarrow\dfrac{5}{3}:x=\dfrac{1}{2}-\dfrac{1}{5}=\dfrac{3}{10}\)
\(\Leftrightarrow x=\dfrac{5}{3}:\dfrac{3}{10}=\dfrac{5}{3}\cdot\dfrac{10}{3}\)
hay \(x=\dfrac{50}{9}\)
Vậy: \(x=\dfrac{50}{9}\)
c) Ta có: \(\dfrac{4}{9}-\dfrac{5}{3}\cdot x=-2\)
\(\Leftrightarrow\dfrac{5}{3}x=\dfrac{4}{9}+2=\dfrac{22}{9}\)
\(\Leftrightarrow x=\dfrac{22}{9}:\dfrac{5}{3}=\dfrac{22}{9}\cdot\dfrac{3}{5}\)
hay \(x=\dfrac{22}{15}\)
Vậy: \(x=\dfrac{22}{15}\)
d) Ta có: \(\dfrac{5}{7}:x-3=\dfrac{-2}{7}\)
\(\Leftrightarrow\dfrac{5}{7}:x=\dfrac{-2}{7}+3=\dfrac{19}{21}\)
\(\Leftrightarrow x=\dfrac{5}{7}:\dfrac{19}{21}=\dfrac{5}{7}\cdot\dfrac{21}{19}\)
hay \(x=\dfrac{15}{19}\)
Vậy:\(x=\dfrac{15}{19}\)
S
20 tháng 12 2022
a) x + 118 = 218
x = 218 – 118
x = 100
b) 18 – x = -17
X = 18 – (-17)
X = 35
c) (-18) – x = -17
X = (-18) – (-17)
X = -1
d)124 + (118 – x) = 217
118 – x = 93
X = 118 – 93
X = 25
e) (3x – 6).3 = 34
(3x – 6).3 = 81
3x – 6 = 27
3x = 33
ð X = 11
g) 23.(42 – x) = 46
42 – x = 2
ð X = 40
S
20 tháng 12 2022
h) 84 – (3x + 8) = 34
3x + 8 = 84 – 34
3x + 8 = 50
3x = 50 – 8
3x = 42
X = 42 : 3
ð X = 14
i) 3.(2x + 1) – 19 = 14
3.(2x + 1) = 14 + 19
3.(2x + 1) = 33
2x + 1 = 33 : 3
2x + 1 = 11
2x = 11 – 1
2x = 10
X = 10 : 2
ð X = 5
k) 6x – 302 = 23.5
6x – 302 = 40
6x = 40 + 302
6x = 342
X = 342 : 6
ð X = 57
m) (x – 1)2 = 81
(x – 1)2 = 92
ð X – 1 = 9
ð X = 9 + 1
ð X = 10
n) 2x+1 – 5 = 27
2x+1 = 27 + 5
2x+1 = 32
2x+1 = 25
ð X = 4
CT
6
6 tháng 12 2021
\(\text{ a) 12+(4−x)=−5}\\ 4-x=-5-12\\ 4-x=-17\\ x=4-\left(-17\right)\\ x=21\)
19 tháng 9 2017
\(\frac{a}{b}\cdot4+\frac{1}{6}=\frac{17}{6}\)
\(\frac{a}{b}\cdot4=\frac{17}{6}-\frac{1}{6}\)
\(\frac{a}{b}\cdot4=\frac{8}{3}\)
\(\frac{a}{b}=\frac{8}{3}:4\)
\(\frac{a}{b}=\frac{2}{3}\)
PA
1
10 tháng 8 2021
a: Ta có: \(-x^2+4x+5\)
\(=-\left(x^2-4x-5\right)\)
\(=-\left(x^2-4x+4-9\right)\)
\(=-\left(x-2\right)^2+9\le9\forall x\)
Dấu '=' xảy ra khi x=2
b: Ta có: \(-x^2-7x+4\)
\(=-\left(x^2+7x-4\right)\)
\(=-\left(x^2+2\cdot x\cdot\dfrac{7}{2}+\dfrac{49}{4}-\dfrac{65}{4}\right)\)
\(=-\left(x+\dfrac{7}{2}\right)^2+\dfrac{65}{4}\le\dfrac{65}{4}\forall x\)
Dấu '=' xảy ra khi \(x=-\dfrac{7}{2}\)
a) x + 17 = 5
x = 5 - 17
x = 5 + ( - 17 )
x = - 12
Vậy x = - 12
b) x - 34 = - 6
x = - 6 + 34
x = 34 - 6
x = 28
Vậy x = 28