1)

a) \(=15x^3-20x^2+10x\)

b) \(=3x^4-x^3+4x^2-9x^3+3x-12x=3x^4-10x^3+4x^2-9x\)

2) 

a) \(\Rightarrow x\left(x^2-6x+12\right)=0\)

\(\Rightarrow x=0\)(do \(x^2-6x+12=\left(x^2-6x+\dfrac{36}{4}\right)+3=\left(x-\dfrac{6}{2}\right)^2+3\ge3>0\))

b) \(\Rightarrow\left(x+3\right)^3=0\Rightarrow x=-3\)

(3x²-5x+2)+(3x²+5x)= bao nhiêu ạ

Giúp em vs ạ . Em cảm ơn

6x²-3xy+17x-4y+5=0

⇔ -3xy-4y=-6x²-17x-5

⇔ 3xy+4y=6x²+17x+5

⇔ y(3x+4)=6x²+17x+5

6x²+17x+5 ⋮ 3x-4 vì x, y ∈ Z

⇔ 6x²+17x+12-7 ⋮ 3x+4

⇔ 6x²+8x+9x+12-7 ⋮ 3x+4

⇔ 2x(3x+4)+3(3x+4)-7 ⋮ 3x+4

=> 7 ⋮ 3x+4

=> 3x+4 ∈ Ư(7)={-1,1,-7,7}

3x+4=1 ⇔ x=-1 (lấy)

3x+4=-1 ⇔ x=\(\dfrac{-5}{3}\) (loại)

3x+4=-7 ⇔ x=\(\dfrac{-11}{3}\)(loại)

3x+4=7 ⇔ x=1 (lấy)

thay vào tính thì y={-6,4} (bạn tự làm nhá)

vậy (x,y)={(-1,1),(-6,4)}

\(\Leftrightarrow-\dfrac{2}{5}\left(4x-3\right)^2=-\dfrac{5}{18}\)

\(\Leftrightarrow\left(4x-3\right)^2=\dfrac{25}{36}\)

\(\Leftrightarrow4x-3\in\left\{\dfrac{5}{6};-\dfrac{5}{6}\right\}\)

hay \(x\in\left\{\dfrac{23}{24};\dfrac{13}{24}\right\}\)

Ta có : |17x - 5| - |17x + 5| = 0

=> |17x - 5| = |17x + 5|

Có 2 TH xảy ra :

TH1 : 17x - 5 = 17x + 5

=> 17x - 17x = 5 + 5

=> 0 = 10 (vô lý)

TH2 : 17x - 5 = - (17x + 5)

=> 17x - 5 = - 17x - 5

=> 17x + 17x = -5 + 5

=> 34x = 0

=> x = 0

\(a,\Leftrightarrow\dfrac{\left(n+15\right)\left(15-n+1\right)}{2}=0\\ \Leftrightarrow\left[{}\begin{matrix}n=-15\\n=14\left(l\right)\end{matrix}\right.\Leftrightarrow n=-15\\ b,\Leftrightarrow\dfrac{\left(35+n\right)\left(35-n+1\right)}{2}=0\\ \Leftrightarrow\left[{}\begin{matrix}n=-35\left(n\right)\\n=34\left(l\right)\end{matrix}\right.\Leftrightarrow n=-35\)

\(a,\Leftrightarrow25x^2-70x+49-25x^2=32\\ \Leftrightarrow-70x=-17\Leftrightarrow x=\dfrac{17}{70}\\ b,\Leftrightarrow x^2-6x+9+x^2+2x+1-5=0\\ \Leftrightarrow2x^2-4x+5=0\\ \Leftrightarrow2\left(x^2-2x+1\right)+3=0\\ \Leftrightarrow2\left(x-1\right)^2=-3\Leftrightarrow\left(x-1\right)^2=-\dfrac{3}{2}\left(\text{vô lí}\right)\\ \Leftrightarrow x\in\varnothing\)

Đơn thức là: x/(3y), x, -2/3, xy-2, 0

Đơn thức là \(-5xy^2;x;-\dfrac{2}{3};0\)

17x{33-[22+(14+11):7]}

=17x{33-[22+25:7]}

SAI ĐỀ RỒI BẠN ƠI!

ĐỀ SAI HẢ BẠN ƠI?

\(17.\left\{33-\left[22+\left(14+11\right):7\right]\right\}\)

\(=17.\left\{33-\left[22+25:7\right]\right\}\)

\(=17.\left\{33-\left[22+\frac{25}{7}\right]\right\}=17.\left\{33-\left[25\frac{4}{7}\right]\right\}\)

\(=17.\left\{7\frac{3}{7}\right\}=17.\frac{52}{7}\)

\(=126\frac{2}{7}=\frac{884}{7}\)