5x + 2x =62 - 50
5x + x = 150 : 2+ 3
6x + x = 511 : 59 - 31
5x + 3x = 36 ; 33 .4 +12
4x + 2x = 68 - 219 : 2 16
5x + x = 39 - 311 : 39
7x - x = 521 : 519 + 3. 22 - 70
7x - 2x = 617 : 615 + 44 : 11
a) 5x + 2x = 62 - 50
b) 5x + x = 150 : 2 + 3
c) 6x + x = 511 : 59 + 31
d) 5x + 3x = 36 : 33.4 + 12
4x + 2x = 68 – 219 : 216
https://hoc24.vn/cau-hoi/a-5x-2x-62-50b-5x-x-150-2-3c-6x-x-511-59-31d-5x-3x-36-334-124x-2x-68-219-216.2785429565572
a: \(\Leftrightarrow7x=35\)
hay x=5
b: \(\Leftrightarrow6x=78\)
hay x=13
Tìm x biết a 3 2x 95b 9 . 5 x 3 6.56 3 . 56c 5x 4 3 . 5x 3 511 . 2d 3x 2 4 . 3x 1 1 . 36e 5x 3 105.6344.33 Giups mk vs nhé các cậu .
a) (x\(^2\)+ 3x - 3)\(^2\) - 12x\(^2\) - 36x + 36 = 0
b) x\(^3\) + 1 + 3(x\(^2\) - x +1) = 0
c) x\(^3\) - 2x\(^2\) + 4x - 8 = 0
Giúp mình với ạ
Tìm x,biết:
a) x^2-36=0
b) (3x-5)^2-(x+6)^2=0
c) (5x-4)^2-49x^2=0
d)4x^3-36x=0
e) 2/3x(x^2-4)=0
a) \(x^2-36=0\)
\(\Leftrightarrow x^2=36\)
\(\Leftrightarrow x=\pm\sqrt{36}=\pm6\)
b) \(\left(3x-5\right)^2-\left(x+6\right)^2=0\)
\(\Leftrightarrow\left(3x-5-x-6\right)\left(3x-5+x+6\right)=0\)
\(\Leftrightarrow\left(2x-11\right)\left(4x+1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{11}{2}\\x=\frac{-1}{4}\end{cases}}\)
d) \(4x^3-36x=0\)
\(\Leftrightarrow4x\left(x^2-9\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}4x=0\\x^2-9=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm3\end{cases}}}\)
Vậy...
Tìm x
12(x – 1) = 0
45 + 5(x – 3) = 70
3.x – 18 : 2 = 12
5x + 2x = 62 - 50
5x + x = 150 : 2 + 3
\(a,12\left(x-1\right)=0\\ x-1=0\\ x=1\\ b,45+5\left(x-3\right)=70\\ 5\left(x-3\right)=25\\ x-3=5\\ x=8\\ c,3.x-18:2=12\\ 3.x-9=12\\ 3.x=21\\ x=7\)
12(x-1)=0
(x-1)=0:12
x-1=0
x=0+1
x= 1
Vậy x= 1
12 ( x - 1 ) = 0
x - 1 = 0 : 12
x - 1 = 0
=> x = 1
giải phương trình sau:
a) \(4x^2+\left(8x-4\right).\sqrt{x}-1=3x+2\sqrt{2x^2+5x-3}\)
b) \(8x^3-36x^2+\left(1-3x\right)\sqrt{3x-2}-3\sqrt{3x-2}+63x-32=0\)
c) \(2\sqrt[3]{3x-2}-3\sqrt{6-5x}+16=0\)
d) \(\sqrt[3]{x+6}-2\sqrt{x-1}=4-x^2\)
Bài 1 phân tích thành nhân tử bằng phương pháp phối hợp nhiều phương pháp
1) 5x^2y - 30xy^2 + 45y^3
2) 3x^3 +3x^2 - 36x
3) x^4 - 4x^3 - 4x^2 +16
4) x^2 (y- z) + y^2 (z - x ) + z^2 ( x- y)
5) 6a^2 -ab - 2b^2 + 3a - 2b
6) x^2 - y^2 - 2x + 2y
7) Xy - 5y + 2x -10
8) 5x^3 - 20x
9) x^3 - 3x^2 - 3x +1
10) 2x^3 + x^2 -8x -4
11) (x^2 + 9)^2 - 36x^2
1.a) Rút gọn D= 2x*(10x^2-5x-2)-5x*(4x^2-2x-1)
b) Tính gt biểu thức E(x)= x^5-13x^4=13x^3-13x^2+13x+2012 tại x=12
2. Tìm x biết
a) 2x*(x-5)-x*(3+2x)=26
b) (12x-5)*(3x-1)-36x^2-6
3. CM rằng các biểu thức sau không phụ thuoccj vào x
a) D=x*(5x-3)-x^2*(x-1)+x*(x^2-6x)-10+3x
1/
a/ \(D=2x\left(10x^2-5x-2\right)-5x\left(4x^2-2x-1\right)\)
\(D=2x\left[10\left(x^2-\frac{1}{2}x-\frac{1}{5}\right)\right]-5x\left[4\left(x^2-\frac{1}{2}x-\frac{1}{4}\right)\right]\)
\(D=20x\left(x^2-\frac{1}{2}x-\frac{1}{5}\right)-20x\left(x^2-\frac{1}{2}x-\frac{1}{4}\right)\)
\(D=20x^3-10x^2-4x-20x^3+10x^2+5x\)
\(D=x\)
b/ Mình xin sửa lại đề:
Tính giá trị biểu thức \(E\left(x\right)=x^5-13x^4+13x^3-13x^2+13x+2012\)
Tại x = 12
\(E\left(x\right)=x^5-\left(x+1\right)x^4+\left(x+1\right)x^3-\left(x+1\right)x^2+\left(x-1\right)x+2012\)
\(E\left(x\right)=x^5-x^5-x^4+x^4+x^3-x^3-x^2+x^2-x+2012\)
\(E\left(x\right)=2012-x\)
\(E\left(x\right)=2000\)
2/
a/ \(2x\left(x-5\right)-x\left(3+2x\right)=26\)
<=> \(2x^2-10x-3x-2x^2=26\)
<=> \(-13x=26\)
<=> \(x=-2\)
b/ Bạn vui lòng coi lại đề.
3a/ Ta có \(D=x\left(5x-3\right)-x^2\left(x-1\right)+x\left(x^2-6x\right)-10+3x\)
\(D=5x^2-3x-x^3+x^2+x^3-6x^2-10+3x\)
\(D=-10\)
Vậy giá trị của D không phụ thuộc vào x (đpcm)
7.38. Tìm giá trị của x, biết rằng:
a) 3x\(^2\) - 3x(x - 2) = 36
b) 5x(4x\(^2\) - 2x +1) - 2x(10x\(^2\) - 5x +2) = -36
\(a,3x^2-3x\left(x-2\right)=36\\ \Leftrightarrow3x^2-3x^2+6x=36\\ \Leftrightarrow6x=36\\ \Leftrightarrow x=6\\ b,5x\left(4x^2-2x+1\right)-2x\left(10x^2-5x+2\right)=-36\\ \Leftrightarrow20x^3-10x^2+5x-20x^3+10x^2-4x+36=0\\ \Leftrightarrow\left(20x^3-20x^3\right)+\left(-10x^2+10x^2\right)+\left(5x-4x\right)=-36\\ \Leftrightarrow x=-36\)
Rút gọn :
1. (2x-5)(3x+1)-(x-3)^2+(2x+5)^2-(3x+1)^3
2. (2x-1)(2x+1)-3x-2)(2x+3)-(x-1)^3+(2x+3)^3
3. (x-2)(x^2+2x+4)-(3x-2)^3+(3x-4)^2
4. (7x-1)(8x+2)-(2x-7)^2-(x-4)^3-(3x+1)^3
5. (5x-1)(5x+1)-(x+3)(x^2-3x+9)-(2x+4)^2-(3x-4)^2+(2x-5)^3
6. (4x-1)(x+2)-(2x+5)^2-(3x-7)^2+(2x+3)^3=(3x-1)^3
1: \(=6x^2+2x-15x-5-x^2+6x-9+4x^2+20x+25-27x^3-27x^2-9x-1\)
=-27x^3-18x^2+4x+10
2: =4x^2-1-6x^2-9x+4x+6-x^3+3x^2-3x+1+8x^3+36x^2+54x+27
=7x^3+37x^2+46x+33
5:
\(=25x^2-1-x^3-27-4x^2-16x-16-9x^2+24x-16+\left(2x-5\right)^3\)
\(=8x^3-60x^2+150-125+12x^2-x^3+8x-60\)
=7x^3-48x^2+8x-35