số quả cam là 25+35+20=80 quả

tik mik nha

\(17x+\dfrac{17}{9x}\ge\dfrac{34}{3}\)

tương tự.....

suy ra 

\(17\left(x+y+z\right)+\dfrac{17}{9}\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)\ge\dfrac{34}{3}.3=34\)

lại có 

\(\dfrac{1}{9}\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)\ge\dfrac{9}{x+y+z}.\dfrac{1}{9}=1\)

nên

\(17\left(x+y+z\right)+\dfrac{17}{9}\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)+\dfrac{1}{9}\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)=17\left(x+y+z\right)+2\left(\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}\right)\ge35\)

=x^10

tik mik nhaaa

13;13^3;177 x 13^5 chia hết cho 13

mà 12 không chia hết cho 13

nên C không chia hết cho 13

tik mik nha

25 - ( 25 - x ) = 12 + ( 42 - 65 )

x=12+(-13)=-1

tik mik nha

mik nhầm nha 1351 ms đúng

tik mik nha

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