`@` `\text {Ans}`
`\downarrow`
`1,`
`a,`
\(3^{11}\div3^9-147\div7^2\)
`=`\(3^2-147\div49\)
`=`\(9-3=6\)
`b,`
\(180-10\times\left(2023^0+3^6\div3^4\right)\)
`=`\(180-10\times\left(1+3^2\right)\)
`=`\(180-10\times\left(1+9\right)\)
`= 180 - 10 \times 10`
`= 180 - 100`
`= 80`
`c,`
\(3^2\times5-2^2\times7+8^3\)
`= 9 \times 5 - 4 \times 7 + 512`
`= 45 - 28 + 512`
`= 529`
`d,`
\(295-\left(31-2^2\times5\right)^2\)
`= 295 - (31 - 4 \times 5)^2`
`= 295 - (31 - 20)^2`
`= 295 - 11^2`
`= 295 - 121`
`= 174`
`2,`
`a,`
\(45-\left(x+9\right)=6\)
`=> x + 9 = 45 - 6`
`=> x + 9 = 39`
`=> x = 39 - 9`
`=> x = 30`
Vậy, `x = 30`
`b,`
\(3^x=27\)
`=> 3^x = 3^3`
`=> x = 3`
Vậy, `x = 3`
`c,`
\(\left(x+2\right)^3=125\)
`=> (x+2)^3 = 5^3`
`=> x+2 = 5`
`=> x = 5 - 2`
`=> x = 3`
Vậy, `x = 3`
`3,`
`a,`
`120 = 2^3 \times 15`
Ước của `120` là:
`\text {Ư(120) = }` \(\left\{1;2;3;4;5;6;8;10;12;15;20;24;30;40;60;120\right\}\)
`b,`
`210 = 2 \times 3 \times 5 \times 7`
`\text {Ư(210) = } `\(\left\{1;2;3;5;6;7;10;14;15;21;30;35;42;70;105;210\right\}\)
`c,`
`373 = 1 \times 373`
`\text {Ư(373) = }`\(\left\{1;373\right\}\)
