gpt
c)√x+2√x-1=2
d)√2x2-2x+1
Bài 1: Thu gọn các biểu thức sau
a)(2x2 + 5x - 2)(2x2 - 4x +3)
b)(2x -3)(3x - 2) - 3x(2x - 5)
c)(x -1)(x2 + x + 1) - (x + 1)(x2 - x +1)
d)(x2 + x - 1)(x2 - x + 1)
e)(2 + 3y)2 - (2x -3y)2 -12xy
d)(x2 - 4x)(5 + 2x - x2)
cảm ơn!giúp mình với chiều nay ktra 15ph T_T
Bài 5: Tìm nghiệm của các đa thức sau: Dạng 1: a) 4x + 9 b) -5x + 6 c) 7 – 2x d) 2x + 5 Dạng 2: a) ( x+ 5 ) ( x – 3) b) ( 2x – 6) ( x – 3) c) ( x – 2) ( 4x + 10 ) Dạng 3: a) x2 -2x b) x2 – 3x c) 3x2 – 4x d) ( 2x- 1)2 Dạng 4: a) x2 – 1 b) x2 – 9 c)– x 2 + 25 d) x2 - 2 e) 4x2 + 5 f) –x 2 – 16 g) - 4x4 – 25 Dạng 5: a) 2x2 – 5x + 3 b) 4x2 + 6x – 1 c) 2x2 + x – 1 d) 3x2 + 2x – 1
a) 3x(x+1)-x(3x+2)
b) 2x(x2-5x+6)+(x-1)(x+3)
c) (x2-xy+y2)-(x2+2xy+y2)
d) (2/5xy+x-y)-(3x+4y)-2/5xy
e) 2xy(x2-4xy+4y2)
f) (x+y)(xy+5)
g) (x3-2x2-x+2):(x-1)
h) (2x2+3x-2):(2x-1)
Bài 2. Tính:
a. (x – 2y)2
b. (2x2 +3)2
c. (x – 2)(x2 + 2x + 4)
d. (2x – 1)3
\(\text{a. (x – 2y)^2=x^2- 2x2y+ (2y)^2 =x^2-4xy+4y^2 }\)
\(\text{b. (2x^2 +3)^2= (2x^2)^2+2.2x.3+3^2=16x^4+12x+9}\)
\(\text{c. (x – 2)(x^2 + 2x + 4)=x^3-2^3=x^3-6 }\)
\(\text{d. (2x – 1)^3= 2x^3-3.(2x)^2.1+3.2x.1^2-1^3=8x^3-12x^2+6x-1}\)
Tìm x, biết:
a) 2(5x-8)-3(4x-5) = 4(3x-4) + 11;
b) 2 x ( 6 x - 2 x 2 ) + 3 x 2 ( x - 4 ) = 8;
c) 2 ( x 3 - 1 ) - 2 x 2 ( x + 2 x 4 ) + ( 4 x 5 + 4 ) x = 6;
d)(2x)2(4x-2)-(x3 -8x2) = 15.
a) x = 2 7 b) x = 2.
c) x = 2 d) x = 1.
Bài 2: Tính:
a) (x-2y)2; b) (2x2+3)3; c) (x-2)(x2+2x+4); d) (2x-1)3
Tìm số nguyên x biết:
a) 12-(2x2-3)=7
b) 3x2-12=2x2+4
c) 2x-3.(2x+1)=4x-5.(x-3)
d) (x-2).(x+5)=0
Làm 1 câu bất kì cũng dc ạ!
a, 12 - (2\(x^2\) - 3) = 7
2\(x^2\) - 3 = 12 - 7
2\(x^2\) - 3 = 5
2\(x^2\) = 8
\(x^2\) = 4
\(\left[{}\begin{matrix}x=-2\\x=2\end{matrix}\right.\)
a) \(12-\left(2x^2-3\right)=7\\ 12-2x^2+3=7\\ 15-2x^2=7\\ 2x^2=15-7=8\\ x^2=8:2=4\\ x=\pm2\)
b) \(3x^2-12=2x^2+4\\ 3x^2-2x^2=12+4\\ x^2=16\\ x=\pm4\)
b, 3\(x^2\) - 12 = 2\(x^2\) + 4
3\(x^2\) - 2\(x^2\) = 12 + 4
\(x^2\) = 16
\(\left[{}\begin{matrix}x=-4\\x=4\end{matrix}\right.\)
a. (x – 1)(5x + 3) = (3x – 8)(x – 1)
b. 3x(25x + 15) – 35(5x + 3) = 0
c. (2 – 3x)(x + 11) = (3x – 2)(2 – 5x)
d. (2x2 + 1)(4x – 3) = (2x2 + 1)(x – 12)
e. (2x – 1)2 + (2 – x)(2x – 1) = 0
f. (x + 2)(3 – 4x) = x2 + 4x + 4
\(a,\left(x-1\right)\left(5x+3\right)=\left(3x-8\right)\left(x-1\right)\)
\(\left(x-1\right)\left(5x+3-3x+8\right)=0\)
\(\left(x-1\right)\left(2x+11\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-1=0\\2x+11=0\end{cases}\Rightarrow\orbr{\begin{cases}x=1\\2x=-11\end{cases}\Rightarrow}\orbr{\begin{cases}x=1\\x=-\frac{11}{2}\end{cases}}}\)
\(b,3x\left(25x+15\right)-35\left(5x+3\right)=0\)
\(15x\left(5x+3\right)-35\left(5x+3\right)=0\)
\(\left(5x+3\right).5\left(3x-7\right)=0\)
\(\Rightarrow\orbr{\begin{cases}5x+3=0\\5\left(3x-7\right)=0\end{cases}\Rightarrow\orbr{\begin{cases}5x=-3\\3x-7=0\end{cases}\Rightarrow}\orbr{\begin{cases}x=-\frac{3}{5}\\3x=7\end{cases}\Rightarrow}\orbr{\begin{cases}x=-\frac{3}{5}\\x=\frac{7}{3}\end{cases}}}\)
\(c,\left(2-3x\right)\left(x+11\right)=\left(3x-2\right)\left(2-5x\right)\)
\(\left(3x-2\right)\left(2-5x\right)+\left(3x-2\right)\left(x+11\right)=0\)
\(\left(3x-2\right)\left(2-5x+x+11\right)=0\)
\(\left(3x-2\right)\left(13-4x\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3x-2=0\\13-4x=0\end{cases}\Rightarrow\orbr{\begin{cases}3x=2\\4x=13\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{2}{3}\\x=\frac{13}{4}\end{cases}}}\)
còn đâu tự lm lười :_#
a) (3x3 — 2x2 + x +2).(5x2)
b) 3x4(-2x3+5x2-2/3x+1/3)
c) (2x —3)(x2 + 2x — 4)
d) (x -3)(x +7)-(x+5)(x-1)
help plssssss
a: \(5x^2\left(3x^3-2x^2+x+2\right)\)
\(=15x^5-10x^4+5x^3+10x^2\)
b: \(3x^4\left(-2x^3+5x^2-\dfrac{2}{3}x+\dfrac{1}{3}\right)\)
\(=-6x^7+15x^6-2x^5+x^4\)