Rút gọn:
a. .2x2 + 3(x-1)(x+1) - 5x(x+1)
b. (8-5x)(x+2)+4(x-2)(x+1)+2(x-2)(x+2)+10
c. 4(x-1)(x+5)-(x+2)(x+5)-3(x-1)(x+2)
Rút gọn:
a)(5x-4)(5x+4)-(5x-4)2
b)(5x+3)2-(4x-1)2-(9x2+8)
c)2(x-5y)(x+5y)+(x+5y)2+(x-5y)2
a, \(\left(5x-4\right)\left(5x+4\right)-\left(5x-4\right)^2=\left(25x^2-16\right)-\left(25x^2-40x+16\right)=40x-32\)
b,\(\left(5x+3\right)^2-\left(4x-1\right)^2-\left(9x^2+8\right)=\left(x+4\right)\left(9x-2\right)-\left(9x^2+8\right)\)
\(=9x^2+34x-8-\left(9x^2+8\right)=34x\)
c,\(2\left(x-5y\right)\left(x+5y\right)+\left(x+5y\right)^2+\left(x-5y\right)^2=\left(2x\right)^2=4x^2\)
1) √(2x-1) <= 8-2x
2) √[(x+1)(4-x)] > x-2
3) √(x-2x^2+1) > 1-x
4) √(x+5) - √(x+4) > √(x+3)
5) √(5x-1) - √(x-1) > √(2x-4)
6) √(x+3) >= √(2x-8) + √(7-x)
7) √(x+2) - √(3-x) < √(5-2x)
8) √(x+1) > 3 - √(x+4)
9) √(5x-1) - √(4x-1)<= 3√x
10) { {√[2(x^2-16)]} / √(x-3) }+ √(x-3) > (7-x) / √(x-3)
Giúp mình 10 câu này với ạaa
Bạn nên viết đề bằng công thức toán và ghi đầy đủ yêu cầu đề để mọi người hiểu đề của bạn hơn nhé.
Bài 1:Thực hiện phép tính
a,(5-2x)(x+3)-4x(x+2) b,(3x+1)(x-3)-4(x+2)(x-2)
c,3(x-4)(x+3)+(x-5)(x+3) d,2x(x-4)+(3x-1)(2x-5)
Bài 2:Tìm x biết
a,5x(x+3)-(5x+2)(x+3)=7
b,(3x-1)(3x+2)-9(x+2)(x-2)=10
c,(x+1)(2x-5)+2(3-x)(x+2)=7
d,(1-3x)(x+2)+3x(x-5)=8
Giải phương trình chứa ẩn ở mẫu:
a. (x+1)/(x-2) - (x-1)(x+2) = 2(x2 + 2)/(x2 - 4)
b. (2x+1)/(x-1) = 5(x-1)/(x+1)
c. (x-1)/(x+2) - (x)/(x-2) = (5x-2)/(4 - x2)
d. (x-2)/(2+x)-(3)/(x-2)= 2(x-11)/(x2 - 2)
e. (x-1)/(x+1)-(x2 + x - 2)/(x+1)= (x+1)/(x-1) - x - 2
f. (x+1)/(x-1)-(x-1)/(x+1)=(4)/(x2 - 1)
g. (3)/4(x-5) + (15)/(50-2x2)= - (7)/6(x+5)
h. (12)/(8+x3)= 1 + (1)/(x+2)
k. (x+25)/(2x2 - 50)-(x+5)(x2 - 5x)= (5-x)(2x2 + 10x)
\(a,\frac{x+1}{x-2}-\frac{x-1}{x+2}=\frac{2\left(x^2+2\right)}{x^2-4}\)
\(\Leftrightarrow\frac{\left(x+1\right)\left(x+2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{\left(x-1\right)\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}=\frac{2x^2+4}{\left(x-2\right)\left(x+2\right)}\)
\(\Rightarrow x^2+2x+x+2-\left(x^2-2x-x+2\right)=2x^2+4\)
\(\Leftrightarrow x^2+3x+2-x^2+2x+x-2=2x^2+4\)
\(\Leftrightarrow6x=2x^2+4\)
\(\Leftrightarrow2x^2+4-6x=0\)
\(\Leftrightarrow2x^2+4-6x=0\)
\(\Leftrightarrow\left(x-1\right)\left(x+3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-1=0\\x+3=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=1\\x=-3\end{cases}}\)
\(b,\frac{2x+1}{x-1}=\frac{5\left(x-1\right)}{x+1}\)
\(\Leftrightarrow\left(2x+1\right)\left(x+1\right)=5\left(x-1\right)\left(x-1\right)\)
\(\Leftrightarrow2x^2+2x+x+1=5\left(x^2-2x+1\right)\)
\(\Leftrightarrow2x^2+3x+1=5x^2-10x+5\)
\(\Leftrightarrow5x^2-2x^2-10x-3x+5-1=0\)
\(\Leftrightarrow3x^2-13x+4=0\)
\(\Leftrightarrow\left(x-4\right)\left(x-\frac{1}{3}\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-4=0\\x-\frac{1}{3}=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=4\\x=\frac{1}{3}\end{cases}}}\)
\(c,\frac{x-1}{x+2}-\frac{x}{x-2}=\frac{5x-2}{4-x^2}\)
\(\Leftrightarrow\frac{x-1}{x+2}-\frac{x}{x-2}=\frac{2-5x}{x^2-4}\)
\(\Leftrightarrow\frac{\left(x-1\right)\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\frac{2-5x}{\left(x-2\right)\left(x+2\right)}\)
\(\Rightarrow x^2-2x-x+2-x^2-2x=2-5x\)
\(\Leftrightarrow-5x+2=2-5x\)
\(\Leftrightarrow-5x+5x=2-2\)
\(\Leftrightarrow0=0\)
=>pt luôn có nghiệm với mọi x.
Giải phương trình chứa ẩn ở mẫu:
a. (x+1)/(x-2) - (x-1)(x+2) = 2(x2 + 2)/(x2 - 4)
b. (2x+1)/(x-1) = 5(x-1)/(x+1)
c. (x-1)/(x+2) - (x)/(x-2) = (5x-2)/(4 - x2)
d. (x-2)/(2+x)-(3)/(x-2)= 2(x-11)/(x2 - 2)
e. (x-1)/(x+1)-(x2 + x - 2)/(x+1)= (x+1)/(x-1) - x - 2
f. (x+1)/(x-1)-(x-1)/(x+1)=(4)/(x2 - 1)
g. (3)/4(x-5) + (15)/(50-2x2)= - (7)/6(x+5)
h. (12)/(8+x3)= 1 + (1)/(x+2)
k. (x+25)/(2x2 - 50)-(x+5)(x2 - 5x)= (5-x)(2x2 + 10x)
Rút gọn biểu thức
a).x(2x2-3)-x2(5x+1)+x2
b).3x(x-2)-5x(1-x)-8(x2-3)
c).1/2x2(6x-3)-x(x2+1/2)+1/2(x+4)
1. Rút Gọn
a) -5x (x-3).(2x+4)-(x+3)(x-3)+(5x-2)(3x+4)
b) (4x-1)x(3x+1)-5x^2x(x-3)-(x-4)x(x-5)-7(x^3-2x^2+x-1)
c) (5x-7)(x-9)-(3-x)(2-5x)-2x(x-4)
d)(5x-4)(x+5)-(x+1)(x^2-6)-5x+19
e)(9x^2-5)(x-3)-3x^2(3x+9)-(x-5)(x+4)-9x^3
g) (x-1)^2 - (x+2)^2
Thanks mn nhiều ạ
\(a,-5x\left(x-3\right)\left(2x+4\right)-\left(x+3\right)\left(x-3\right)+\left(5x-2\right)\left(3x+4\right)\)
\(=-5x\left(2x^2-x-12\right)-\left(x^2-9\right)+15x^2+20x-6x-8\)
\(=-10x^3+5x^2+60x-x^2+9+15x^2+20x-6x-8\)
\(=-10x^3+19x^2+74x+1\)
\(b,\left(4x-1\right)x\left(3x+1\right)-5x^2.x\left(x-3\right)-\left(x-4\right)x\left(x-5\right)\)\(-7\left(x^3-2x^2+x-1\right)\)
\(=\left(4x^2-x\right)\left(3x+1\right)-5x^4-15x^3-\left(x^2-4x\right)\left(x-5\right)\)\(-7x^3+14x^2-7x+7\)
\(=12x^3+x^2-x-5x^4-15x^3-x^3+9x^2+20x\)\(-7x^3+14x^2-7x+7\)
\(=-5x^4-11x^3+24x^2+12x+7\)
\(c,\left(5x-7\right)\left(x-9\right)-\left(3-x\right)\left(2-5x\right)-2x\left(x-4\right)\)
\(=5x^2-52x+63-6+17x-5x^2-2x^2+8x\)
\(=-2x^2-27x+57\)
\(d,\left(5x-4\right)\left(x+5\right)-\left(x+1\right)\left(x^2-6\right)-5x+19\)
\(=5x^2+21x-20-x^3-x^2+6x+6-5x+19\)
\(=-x^3+4x^2+22x+5\)
\(e,\left(9x^2-5\right)\left(x-3\right)-3x^2\left(3x+9\right)-\left(x-5\right)\left(x+4\right)-9x^3\)
\(=9x^3-27x^2-5x+15-9x^3-27x^2-x^2+x+20-9x^3\)
\(=-9x^3-55x^2+4x+35\)
\(g,\left(x-1\right)^2-\left(x+2\right)^2\)
\(=x^2-2x+1-x^2-4x-4\)
\(=-6x-3\)
Rút gọn biểu thức
a) 22 + 3(x-1) (x+1) - 5x (x+1)
b) ( 8-5x ) ( x+2 ) + 4(x-2) (x+1) +2(x-2) (x+2)+10
c) 4(x-1) (x+5)-(x+2) (x+5)-3(x-1)(x+2)
d) (x2-2x+3) (3x-5) - (x2+x-1) (2x+7)
B1:tìm x biết a, (-2+x^2)(x^2-2)(x^2-2)(x^2-2)(x^2-2)=1 b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4) c,(8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1) d, 2x^2+3(x-1)(x+1)=5x(x+1) e, (8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x) f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
Bạn nên viết lại đề bài cho sáng sủa, rõ ràng để người đọc dễ hiểu hơn.
f: =>4(x^2+4x-5)-x^2-7x-10=3(x^2+x-2)
=>4x^2+16x-20-x^2-7x-10-3x^2-3x+6=0
=>6x-24=0
=>x=4
e: =>8x+16-5x^2-10x+4(x^2-x-2)=4-x^2
=>-5x^2-2x+16+4x^2-4x-8=4-x^2
=>-6x+8=4
=>-6x=-4
=>x=2/3
d: =>2x^2+3x^2-3=5x^2+5x
=>5x=-3
=>x=-3/5
b: =>2x^2-8x+3x-12+x^2-7x+10=3x^2-12x-5x+20
=>-12x-2=-17x+20
=>5x=22
=>x=22/5
Chúng ta sẽ giải từng phương trình một:
a. Đặt , ta có: