Tìm x, biết:
a) | x | = 1 5 + 3 4
b) | x − 5 | = − − 5 3 + 1 4
Bài 4. Tìm số nguyên x , biết:
a) |x - 2|= 0 b) |x + 3|= 1 c) -3 |4 - x|= -9 d) |2x + 1|= -2
Bài 5. Tìm số nguyên x, biết:
a) (x + 3)mũ 2 = 36 b) (x + 5)mũ 2 =100 c) (2x - 4)mũ 2 = 0 d) (x - 1)mũ 3 = 27
bài 2:tìm x, biết:
a. x + 1^3 = 2^5 - ( -1^3 )
b. 3^7 - x = 1^4 - ( -3^5 )
a) \(x+1^3=2^5-\left(-1^3\right)\)
\(\Rightarrow x+1=33\)
=> x = 32
b) \(3^7-x=1^4-\left(-3^5\right)\)
\(\Rightarrow2187-x=1+243=244\)
=> x = 1943
a) \(\Leftrightarrow x+1=32+1\)
\(\Leftrightarrow x=32\)
Vậy x = 32
b) \(\Leftrightarrow2187-x=1+243\)
\(\Leftrightarrow2187-x=244\)
\(\Leftrightarrow x=1943\)
Vậy x = 1943
a) \(x+1^3=2^5-\left(-1^3\right)\)
\(x+1=32-\left(-1\right)\)
\(x+1=33\)
\(x=33-1\)
\(x=32\)
b) \(3^7-x=1^4-\left(-3^5\right)\)
\(2187-x=1-\left(-243\right)\)
\(2187-x=244\)
\(x=2187-244\)
\(x=1943\)
Tìm x, biết:
a) \(\dfrac{x}{3}\) - 5 = \(\dfrac{2x}{5}\)
b) 4 + 3x = 8 - x
c) 2 . 3\(^{x+1}\) - 5 . 3\(^x\) = 243
a: =>1/3x-2/5x=5
=>-1/15x=5
=>x=-75
b: =>4x=4
=>x=1
c: =>6*3^x-5*3^x=243
=>3^x=243
=>x=5
Tìm x, biết:
a) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5};\)
b) \(\dfrac{4}{5}+\dfrac{5}{7}:x=\dfrac{1}{6}.\)
Lời giải:
a)
$\frac{4}{7}x=\frac{2}{3}+\frac{1}{5}=\frac{13}{15}$
$x=\frac{13}{15}:\frac{4}{7}=\frac{91}{60}$
b)
$\frac{5}{7}:x=\frac{1}{6}-\frac{4}{5}$
$\frac{5}{7}:x=\frac{-19}{30}$
$x=\frac{5}{7}:\frac{-19}{30}=\frac{-150}{133}$
a) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\)
\(\dfrac{4}{7}.x=\dfrac{1}{5}+\dfrac{2}{3}\)
\(\dfrac{4}{7}.x=\dfrac{13}{15}\)
\(x=\dfrac{13}{15}:\dfrac{4}{7}\)
\(x=\dfrac{91}{60}\)
b) \(\dfrac{4}{5}+\dfrac{5}{7}:x=\dfrac{1}{6}\)
\(\dfrac{5}{7}:x=\dfrac{1}{6}-\dfrac{4}{5}\)
\(\dfrac{5}{7}:x=\dfrac{-19}{30}\)
\(x=\dfrac{5}{7}:\dfrac{-19}{30}\)
\(x=\dfrac{-150}{133}\)
1. Tìm số nguyên x, y biết:
a) \(^{3^{4-x}}=27\)
b) \(^{3^{-1}}.^{4^x}+3.^{4^x}=\dfrac{5}{3}.^{2^7}\)
1) Thực hiện phép tính:
a) (-3+4):2 b) -4+(-5)-17 c) 4-[(-11)-(2+5)]
5 9 7 9 9 4 3 6 9 3
2) Tìm x biết:
a) 2+7:x=5 b) (-0,75 x +5).4-(-1)=-5 c)-x+5=1,2 d)2+2x=1
3 4 6 2 7 3 6 3 3 2
3) Tìm số nguyên x,y biết:
x-1=1
4 y 2
Bạn ơi, bạn viết lại đề đi. Khó nhìn quá
Tìm x biết:
a) \(x:1\frac{2}{7} = - 3,5\)
b) \(0,4.x - \frac{1}{5}.x = \frac{3}{4}\)
a) \(1\frac{2}{7} = 1 + \frac{2}{7} = \frac{9}{2}\)
\(\begin{array}{l}x:1\frac{2}{7} = - 3,5\\x:\frac{9}{7} = - \frac{7}{2}\\x = - \frac{7}{2}.\frac{9}{7}\\x = - \frac{9}{2}\end{array}\)
b) \(0,4.x - \frac{1}{5}.x = \frac{3}{4}\)
\(\begin{array}{l}\frac{2}{5}.x - \frac{1}{5}.x = \frac{3}{4}\\\left( {\frac{2}{5} - \frac{1}{5}} \right).x = \frac{3}{4}\\\frac{1}{5}.x = \frac{3}{4}\\x = \frac{3}{4}:\frac{1}{5}\\x = \frac{3}{4}.5\\x = \frac{{15}}{4}\end{array}\)
tìm \(x\) là số tự nhiên biết:
a)\(\dfrac{2}{3}+\dfrac{3}{4}< x< 1\dfrac{1}{3}+\dfrac{4}{5}\) b)\(\dfrac{5}{6}-\dfrac{1}{4}< x< 2\dfrac{1}{3}-\dfrac{2}{5}\)
Tìm số thập phân x biết:
a) \(^{\text{x}}\)\(^{ }\)+ \(\dfrac{3}{4}\)= \(\dfrac{4}{5}\) | b) \(^{\text{x}}\) - \(\dfrac{1}{2}\) = \(\dfrac{5}{8}\) | c) \(^{\text{x}}\) x \(\dfrac{5}{6}\) = \(\dfrac{4}{5}\) | d)\(^{\text{x}}\) : \(\dfrac{5}{8}\) = \(\dfrac{1}{25}\) |
a) \(x=0,05\)
b) \(x=1,125\)
c) \(x=0,96\)
d) \(x=0,025\)
Bạn tự làm đi dễ mà . Cố mag vận động đầu óc đừng copy làm bài nữa khó lắm mới hỏi thôi
bài 45: Tìm x, biết:
a) x=\(\dfrac{-1}{2}+\dfrac{3}{4}\); b) \(\dfrac{x}{5}=\dfrac{5}{6}+\dfrac{-19}{30}\)
a, x= \(\dfrac{1}{4}\)
b, x= \(\dfrac{1}{5}\)
x=-2/4+3/4 x=1/4
6x/30=25/30+-19/30 6x/30=6/30 6x=6 x=1