-3/25 : ( x+3/5 ) + 12 = -3
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.



\(=\dfrac{7}{12}\cdot\left(25\dfrac{3}{5}-31\dfrac{3}{5}\right)=\dfrac{7}{12}\left(-6\right)=-\dfrac{7}{2}\)

a) 4.25-12.5+170:10
=100-60+17
=40+17
=57
b) (7+33:32).4-3
=(7+3).4-3
=10.4-3
=40-3
=37
c) 12:{400:[500-(125+25.7)]}
=12:{400:[500-(125+175)]}
=12:{400:[500-300]}
=12:{400:200}
=12:2
=6
d) 168+{[2.(24+32)-2560]:72}
=168+{[2.(16+9)-1]:49}
=168+{[2.25-1]:49}
=168+{[50-1]:49}
=168+{49:49}
=168+1
=169

\(\left(\frac{12}{25}\right)^x=\left(\frac{5}{3}\right)^{-2}-\left(-\frac{3}{5}\right)^4\)
=> \(\left(\frac{12}{25}\right)^x=\frac{9}{25}-\frac{81}{625}\)
=> \(\left(\frac{12}{25}\right)^x=\frac{225}{625}-\frac{81}{625}=\frac{144}{625}\)
=> \(\left(\frac{12}{25}\right)^x=\left(\frac{12}{25}\right)^2\)
Vậy x = 2
Bài làm :
Ta có :
\(\left(\frac{12}{25}\right)^x=\left(\frac{5}{3}\right)^{-2}-\left(-\frac{3}{5}\right)^4\)
\(\Leftrightarrow\left(\frac{12}{25}\right)^x=\frac{9}{25}-\frac{81}{625}\)
\(\Leftrightarrow\left(\frac{12}{25}\right)^x=\frac{225}{625}-\frac{81}{625}=\frac{144}{625}\)
\(\Leftrightarrow\left(\frac{12}{25}\right)^x=\left(\frac{12}{25}\right)^2\)
\(\Leftrightarrow x=2\)
Vậy x=2

\(a.\dfrac{12+x}{42}=\dfrac{35}{42}\Leftrightarrow12+x=35\Leftrightarrow x=23\)
\(b.\dfrac{25-x}{40}=\dfrac{3}{8}\Leftrightarrow\dfrac{25-x}{40}=\dfrac{15}{40}\Leftrightarrow25-x=15\Leftrightarrow x=10\)
\(c.\dfrac{13+x}{20}=\dfrac{3}{4}\Leftrightarrow\dfrac{13+x}{20}=\dfrac{15}{20}\Leftrightarrow13+x=15\Leftrightarrow x=2\)
\(d.\dfrac{23-x}{25}=\dfrac{20}{25}\Leftrightarrow23-x=20\Leftrightarrow x=3\)

a, (-25) + 276 - (276 - 25)
= (-25) + 276 - 276 + 25
= [ (-25) + 25] - (276 - 276)
= 0 - 0
= 0
b, 24 x 46 + 24 x 53 + 24
= 24 x ( 46 + 53 + 1)
= 24 x 100
= 2400
<=> -3 = -375(x + 3/5)
<=> x = -74/125