`a,(x+1)^2 +x+1`

`=(x+1)^2 + (x+1)`

`=(x+1)(x+1+1)`

`=(x+1)(x+2)`

`b,4x(2y-z)+2y(z-2y)`

`=4x(2y-z)-2y(2y-z)`

`=(4x-2y)(2y-z)`

`=2(2x-y)(2y-z)`

`c, 4(x+y)-2x(x+y)`

`=(4-2x)(x+y)`

`=2(2-x)(x+y)`

`14/28 = (14:14)/(28:14) = 1/2`

`12/8 = (12:4)/(8:4) = 3/2`

sai r 

sai r 

`3651-4^3 . 5^2 +x:3^2 = 5702`

`=>3651-64 . 25 +x:9 = 5702`

`=>3651-1600 +x:9 = 5702`

`=>2051+x:9 = 5702`

`=>x:9 = 5702-2051`

`=>x:9 = 3651`

`=>x = 3651xx9`

`=>x=32859`

đặt tính .-.

`ĐKXĐ: x <= 3`

`sqrt{(x-3)^2} =3-x`

`<=>|x-3|=3-x`

`TH1: x-3 = 3-x`

`<=>x+x=3+3`

`<=>2x=6`

`<=>x=3(tm)`

`TH2: x-3 = -(3-x)`

`<=>x-3=x-3`(luôn đúng `forall x <= 3`)

Vậy phương trình có tập nghiệm `x <= 3`

`a, 29;47;76`

`b,18;25;33`

`c, 19;22;25`

`d,40;74;136`

`ĐKXĐ: x ne 0`

`\(\dfrac{5}{x}+\dfrac{x^2}{3}=0\\ \Leftrightarrow\dfrac{5.3}{3.x}+\dfrac{x^2.x}{3.x}=0\\ \Leftrightarrow\dfrac{15}{3x}+\dfrac{x^3}{3x}=0\\ \Leftrightarrow\dfrac{x^3+15}{3x}=0\\ \Rightarrow x^3+15=0\\ \Leftrightarrow x^3=-15\\ \Leftrightarrow x=\sqrt[3]{-15}\left(tm\right)\)

Vậy \(S=\sqrt[3]{-15}\)