\(9^{9^{9^9}}-9^{9^9}=9^{2a+1}-9^{2b+1}\equiv9-9\equiv0\left(mod10\right)\)
\(9^{9^{9^9}}-9^{9^9}=9^{2a+1}-9^{2b+1}\equiv9-9\equiv0\left(mod10\right)\)
cmr:\(9^{9^{9^9}}-9^{9^9}⋮10\)
chứng minh:
a) \(9^{9^{9^9}}-9^{9^9}⋮10\)
b)\(7^{9^{9^{9^9}}}-7^{9^{9^9}}⋮100\)
CMR :(9x+1).(9x+2).(9x+3).(9x+4) chia hết cho 120 với mọi STN lớn hơn 0
Chứng minh
a) :\(7^{9^{9^{9^9}}}-7^{9^9}⋮100\)
b) \(7^{1976^{1970}}-3^{68^{70}}⋮10\).
Cho a, b, c> 0; a+ b+ c= 9
CMR: \(\frac{a^3+b^3}{ab+9}+\frac{b^3+c^3}{bc+9}+\frac{c^3+a^3}{ca+9}\ge9\)
9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9-9=?
ai làm đúng 1like/ngày!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Cmr:
\(\sqrt[3]{\sqrt[3]{2}-1}=\sqrt[3]{\dfrac{1}{9}}-\sqrt[3]{\dfrac{2}{9}}+\sqrt[3]{\dfrac{4}{9}}\)
Cho 3 số thực không âm thỏa mãn a+b+c=1. CMR
\(\sqrt{7a+9}+\sqrt{7b+9}+\sqrt{7c+9}\ge10\)
9 * 9 * 9 * 9 * 9 = ???