Đăng từng câu đio

,(8x-3).(3x+2)-(4x+7).(x+4)=(2x+1).(5x-1)-33 đúng không bạn

1) (x+6)(3x-1)+x+6=0

⇔(x+6)(3x-1)+(x+6)=0

⇔(x+6)(3x-1+1)=0

⇔3x(x+6)=0

2) (x+4)(5x+9)-x-4=0

⇔(x+4)(5x+9)-(x+4)=0

⇔(x+4)(5x+9-1)=0

⇔(x+4)(5x+8)=0

3)(1-x)(5x+3)÷(3x-7)(x-1)

=\(\frac{\left(1-x\right)\left(5x+3\right)}{\left(3x-7\right)\left(x-1\right)}=\frac{\left(1-x\right)\left(5x+3\right)}{\left(7-3x\right)\left(1-x\right)}=\frac{\left(5x+3\right)}{\left(7-3x\right)}\)

\(x^2\left(x-2\right)+x\left(-3+2x\right)-5x=7\)

\(x^3-2x^2-3x+2x^2-5x=7\)

\(x^3-8x-7=0\)

lam the nao nua

lm tiếp như sau nha bn!!

\(x^3-8x-7=0\)

\(\Leftrightarrow x^3-x^2+x^2-x-7x-7=0\)

\(\Leftrightarrow x^2\left(x-1\right)+x\left(x-1\right)-7\left(x+1\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(x^2+x\right)-7\left(x+1\right)=0\)

\(\Leftrightarrow x\left(x-1\right)\left(x+1\right)-7\left(x+1\right)=0\)

\(\Leftrightarrow\left(x+1\right)\left[x\left(x-1\right)-7\right]=0\)

\(\Leftrightarrow\left(x+1\right)\left(x^2-x-7\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x+1=0\\x^2-x-7=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-1\\x^2-x-7=0\left(1\right)\end{cases}}}\)

Nếu bn hok sang kì II lp 9 thì (1) lm tiếp như sau:

\(x^2-x-7=0\)

\(\Delta=\left(-1\right)^2-4.1.\left(-7\right)=29>0\)

\(\Rightarrow x_1=\frac{1+\sqrt{29}}{2}\)

\(x_2=\frac{1-\sqrt{29}}{2}\)

=.= hok tốt!!

1, x= 2

2, x = 4

**** bạn mình trước nhé

trieu dang sai ket qua vi chua doi dau

\(a,-5x\left(x-3\right)\left(2x+4\right)-\left(x+3\right)\left(x-3\right)+\left(5x-2\right)\left(3x+4\right)\)

\(=-5x\left(2x^2-x-12\right)-\left(x^2-9\right)+15x^2+20x-6x-8\)

\(=-10x^3+5x^2+60x-x^2+9+15x^2+20x-6x-8\)

\(=-10x^3+19x^2+74x+1\)

\(b,\left(4x-1\right)x\left(3x+1\right)-5x^2.x\left(x-3\right)-\left(x-4\right)x\left(x-5\right)\)\(-7\left(x^3-2x^2+x-1\right)\)

\(=\left(4x^2-x\right)\left(3x+1\right)-5x^4-15x^3-\left(x^2-4x\right)\left(x-5\right)\)\(-7x^3+14x^2-7x+7\)

\(=12x^3+x^2-x-5x^4-15x^3-x^3+9x^2+20x\)\(-7x^3+14x^2-7x+7\)

\(=-5x^4-11x^3+24x^2+12x+7\)

\(c,\left(5x-7\right)\left(x-9\right)-\left(3-x\right)\left(2-5x\right)-2x\left(x-4\right)\)

\(=5x^2-52x+63-6+17x-5x^2-2x^2+8x\)

\(=-2x^2-27x+57\)

\(d,\left(5x-4\right)\left(x+5\right)-\left(x+1\right)\left(x^2-6\right)-5x+19\)

\(=5x^2+21x-20-x^3-x^2+6x+6-5x+19\)

\(=-x^3+4x^2+22x+5\)

\(e,\left(9x^2-5\right)\left(x-3\right)-3x^2\left(3x+9\right)-\left(x-5\right)\left(x+4\right)-9x^3\)

\(=9x^3-27x^2-5x+15-9x^3-27x^2-x^2+x+20-9x^3\)

\(=-9x^3-55x^2+4x+35\)

\(g,\left(x-1\right)^2-\left(x+2\right)^2\)

\(=x^2-2x+1-x^2-4x-4\)

\(=-6x-3\)

a. x=-0.5

b.x=\(\frac{-2}{3}\)

a. x= -0,5

b. x= -2/3 nhé bạn

Chú thích: / là phần

Ta có:a, |2x-1|= |2x+3|

<=> 2x - 1 = -(2x + 3) 

=> 2x + 2x = 3 + 1

=> 4x = 4

=> x = 1

Sorry bạn nha, mik chỉ làm câu a thôi