1/ 72

2/ -2;-3

3/ 4 

 4/ 2 HOẶC 3

câu trả lời : ....................................................................................................... . xong rồi nhá

Bài 1: Tính hợp lý (nếu có thể)

a) 5.(-8).(-2).(-3)\(=\left(-2.5\right).\left(\left(-3\right).\left(-8\right)\right)=-10.24=-240\)

c) 147.333+233.(-147)\(=147\left(333-233\right)=147.100=14700\)

b) (-125).8.(-2).5.19\(=\left(-125.8\right).\left(-2.5\right).19=-1000.\left(-10\right).19=190\text{ }000\)

d) (-115).27+33.(-115)\(=-115.\left(27+33\right)=-115.60=-6900\)

Bài 2: Tìm số nguyên x, biết: 

a) 2x+19=15\(\Leftrightarrow2x=15-19=-4\Leftrightarrow x=-2\)

c) 24-(x-3)^3=-3\(\Leftrightarrow\left(x-3\right)^3=27=3^3\Leftrightarrow x-3=3\Leftrightarrow x=6\)

Giải thích các bước giải:

a) `4 vdots x-1`

`=>x-1 inƯ(4)`

`=>x-1 in{+-1;+-2;+-4}`

`=>`$x\in\{2;0;3;-1;5;-3\}$

b) `15 vdots 2x+1`

`=>2x+1 inƯ(15)`

`=>2x+1 in{+-1;+-3;+-5;+-15}`

`=>`$2x \in\{0;-2;2;-4;4;-6;14;-16\}$

`=>`$x\in\{0;-1;1;-2;2;-3;7;-8\}$

c) `x+9 vdotsx+3`

`=>x+3+3 vdotsx+3`

`=>x+3 inƯ(3)`

`=>x+3 in{+-1;+-3}`

`=>`$x\in\{-2;-4;0;-6\}$

d) `3x+5 vdotsx+1`

`=>3x+5 vdots3x+3`

`=>3x+3+2 vdots 3x+3`

`=>3x+3 inƯ(2)`

`=>3x+3 in{+-1;+-2}`

`=>`$3x\in\{-2;-4;-1;-5\}$

`=>`$x\in\left\{\dfrac{-2}{3};\dfrac{-4}{3};\dfrac{-1}{3};\dfrac{-5}{3}\right\}$

a) $4⋮x-1$

$\Rightarrow x-1\in Ư\left(4\right)$

$\Rightarrow x-1\in \{\pm 1;\pm 2;\pm 4\}$

$\Rightarrow$$x\in \{2;0;3;-1;5;-3\}$

b) $15⋮2x+1$

$\Rightarrow 2x+1\in Ư\left(15\right)$

$\Rightarrow 2x+1\in$