Bài 1:
\(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)
\(=\left(-8\right).\left(\frac{3}{4}-\frac{1}{4}\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)
\(=\left(-8\right).\frac{1}{2}:\frac{13}{12}\)
\(=\left(-4\right):\frac{13}{12}\)
\(=-\frac{48}{13}.\)
Bài 2:
a) \(4\frac{1}{3}:\frac{x}{4}=6:0,3\)
\(\Rightarrow\frac{13}{3}:\frac{x}{4}=6:0,3\)
\(\Rightarrow\frac{\frac{13}{3}}{\frac{x}{4}}=\frac{6}{0,3}\)
\(\Rightarrow\frac{13}{3}.0,3=6.\frac{x}{4}\)
\(\Rightarrow\frac{13}{10}=6.\frac{x}{4}\)
\(\Rightarrow\frac{x}{4}=\frac{13}{10}:6\)
\(\Rightarrow\frac{x}{4}=\frac{13}{60}\)
\(\Rightarrow x.60=13.4\)
\(\Rightarrow x.60=52\)
\(\Rightarrow x=52:60\)
\(\Rightarrow x=\frac{13}{15}\)
Vậy \(x=\frac{13}{15}.\)
b) \(\left(2^3:4\right).2^{x+1}=64\)
\(\Rightarrow\left(2^3:2^2\right).2^{x+1}=64\)
\(\Rightarrow2^1.2^{x+1}=64\)
\(\Rightarrow2^1.2^{x+1}=2^6\)
\(\Rightarrow1+x+1=6\)
\(\Rightarrow\left(1+1\right)+x=6\)
\(\Rightarrow2+x=6\)
\(\Rightarrow x=6-2\)
\(\Rightarrow x=4\)
Vậy \(x=4.\)
Chúc em học tốt!
(−2)3.(34−0,25):(94−76)(−2)3.(34−0,25):(94−76)
=(−8).(34−14):(94−76)=(−8).(34−14):(94−76)
=(−8).12:1312=(−8).12:1312
=(−4):1312=(−4):1312
=−4813.=−4813.
Bài 2:
a) 413:x4=6:0,3413:x4=6:0,3
⇒133:x4=6:0,3⇒133:x4=6:0,3
⇒133x4=60,3⇒133x4=60,3
⇒133.0,3=6.x4⇒133.0,3=6.x4
⇒1310=6.x4⇒1310=6.x4
⇒x4=1310:6⇒x4=1310:6
⇒x4=1360⇒x4=1360
⇒x.60=13.4⇒x.60=13.4
⇒x.60=52⇒x.60=52
⇒x=52:60⇒x=52:60
⇒x=1315⇒x=1315
Vậy x=1315.x=1315.
b) (23:4).2x+1=64(23:4).2x+1=64
⇒(23:22).2x+1=64⇒(23:22).2x+1=64
⇒21.2x+1=64⇒21.2x+1=64
⇒21.2x+1=26⇒21.2x+1=26
⇒1+x+1=6⇒1+x+1=6
⇒(1+1)+x=6⇒(1+1)+x=6
⇒2+x=6⇒2+x=6
⇒x=6−2⇒x=6−2
⇒x=4⇒x=4
Vậy x=4.x=4.
