\(\left\{240-\left[76-\left(9-3\right)^2\right]\right\}\div50=\left\{240-\left[76-6^2\right]\right\}\div50=\left\{240-\left[76-36\right]\right\}\div50\)
\(=\left\{240-40\right\}\div50=200\div50=4\)
Tìm x :
\(\left(2+x\right)\div5=6\)
\(2+x=6.5\)
\(2+x=30\)
\(x=30-2\)
\(x=28\)
\(2+x\div5=6\)
\(x\div5=6-2\)
\(x\div5=4\)
\(x=4.5\)
\(x=20\)
So sánh :
a) Ta có : \(125^{80}=\left(5^3\right)^{80}=5^{240}\)
\(25^{118}=\left(5^2\right)^{118}=5^{236}\)
mà \(240>236\)
\(\Rightarrow5^{240}>5^{236}\)
\(\Rightarrow125^{80}>25^{118}\)
b) Ta có : \(2^{161}>2^{160}=\left(2^4\right)^{40}=16^{40}>13^{40}\)
\(\Rightarrow2^{161}>13^{40}\)
