Đáp án:
Giải thích các bước giải:
`3:`
`a)13(x-5)=-169`
`=>x-5=-13`
`=>x=-8`
Vậy `x=-8`
``
`b)2|4-x|=|-8|`
`=>2|4-x|=8`
`=>|4-x|=4`
`=>` \(\left[ \begin{array}{l}4-x=4\\4-x=-4\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=0\\x=8\end{array} \right.\)
Vậy `x\in{0;8}`
``
`4:`
`A=625-(61-17).12+(27+24):17`
`=>A=625-44.12+51:17`
`=>A=625-528+3`
`=>A=100`
````
`B=(-126)-(4^2-5)^2 +870:29`
`=>B=(-126)-(16-5)^2+30`
`=>B=-126-11^2+30`
`=>B=-126-121+30`
`=>B=-217`
``
`5:`
`a)(-5)^3-(3^3+4).(-2)+(3-27):4`
`=-125-31.(-2)+(-24):4`
`=-125+62-6`
`=-69`
``
`b)[(-8)+(-5)](-2)-[3-(-6)]`
`=(-13)(-2)-9`
`=26-9=17`
``
`c)[504-(5^2 . 8 +70):3^2 +6]:(-20)`
`=[504-(25.8+70):9+6]:(-20)`
`=[504-270:9+6]:(-20)`
`=[504-30+6]:(-20)`
`=480:(-20)=-24`
