Tìm x:
X x25=645+255
Tìm x:
x+|-3|=-|-7|
Tính, tính hợp lí nếu có thể:
a. 255 + 312 + 188 + 645
b. 25 + 12.5 - 60
c. 12.75 + 12.7 + 12.18
d. 24.5 - [131 - (13 - 4)2 ]
a) \(255+312+188+645\)
\(=\left(255+645\right)+\left(312+188\right)\)
\(=900+500\)
\(=1400\)
b) \(25+12\cdot5-60\)
\(=25+60-60\)
\(=25\)
c) \(12\cdot75+12\cdot7+12\cdot18\)
\(=12\cdot\left(75+7+18\right)\)
\(=12\cdot100\)
\(=1200\)
d) \(2^4\cdot5-\left[131-\left(13-4\right)^2\right]\)
\(=16\cdot5-\left(131-9^2\right)\)
\(=80-\left(131-81\right)\)
\(=80-50\)
\(=30\)
Tìm X:
X × 12,3 + 0,4 = 148
X × 12,3 + 0,4 = 148
X x 12,3 = 148- 0,4
X x 12,3 = 147,6
x= 147,6 : 12,3
x = 12
tìm x:x-4368=3484*4
Tìm x:
x + 30% x = -1,31
Ta có: x(1+30%)=-1,31
⇒ \(\dfrac{13}{10}\)x =-1,31
⇒ x =-1,31 : \(\dfrac{13}{10}\)
⇒ x = -\(\dfrac{131}{130}\)
x + 30% x = -1,31
\(x+\dfrac{30}{100}x=-1,31\)
x+0,3x=-1,31
x.(0,3+1)=-1,31
x.1,3=-1,31
\(x=\dfrac{-1,31}{1,3}\)
\(x=-\dfrac{131}{130}\)
tìm x:
x^2+x=12
\(x^2+x=12\)
\(\Rightarrow x^2+x-12=0\)
\(\Rightarrow x\left(x-3\right)+4\left(x-3\right)=0\Rightarrow\left(x-3\right)\left(x+4\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-4\end{matrix}\right.\)
Tìm x:
x : 11 - 145 = 526
\(x : 11 - 145 = 526\)
\(x : 11 = 526 + 145\)
\(x : 11 = 671\)
\(x = 671 \) x \(11\)
\(x = 7381\)
Vậy \(x=7381\)
\(\Rightarrow x:11=526-145\)
\(\Rightarrow x:11=381\)
\(\Rightarrow x=381.11\)
\(\Rightarrow x=7381\)
tìm x:
x : 2,3 - 12,4 = 0,94
x : 2,3 -12,4 =0,94
x : 2,3 = 0,94 + 12,4
x : 2,3 = 13,4
x= 13,4 . 2,3
x= 30,682
x : 2,3 - 12,4 = 0,94
x : 2,3 = 0,94 + 12,4
x : 2,3 = 13,34
x = 13,34 x 2,3
x = 30,682.
Chúc học tốt!
x : 2,3 - 12,4 = 0,94
=>x:2,3 =0,94 +12,4
=>x: 2,3 =13,34
=>x =13,34 . 2,3
=>x =30,682
Tìm x:
x-4/12=-5/6
\(x-\dfrac{4}{12}=-\dfrac{5}{6}\)
⇔\(x-\dfrac{1}{3}=-\dfrac{5}{6}\)
⇔\(x=-\dfrac{1}{2}\)
\(\Leftrightarrow x=-\dfrac{1}{2}\)
=>(x-4).6=12.(-5)
=>6x-24=-60
=>6x=-36
=x=-6