giai bai toan bang cach lap phuong trinh
luc 6h o to thu nhat khoi hanh tu A.den 7h30' o to thu 2 cung khoi hanh tu A duoi theo va kip o to thu nhat luc 10h30'.biet van ttoc o to thu 2 hon van toc o to thu nhat 20km/h.tinh van toc moi o to
giup mk bai nay voi mk can gap
hai nguoi cung lam chung 1 cong viec het 6 ngay.nang suat trong 1 ngay cua nguoi thu nhat bang 2/3 nang suat nguoi thu 2 .hoi neu lam 1 minh thi moi nguoi phai lam trong bao lau thoi gian moi xong cong viec
Giải phương trình
1) 5(x - 3) - 4 = 2(x - 1)
2) 5(x - 3) - 2(x - 5) = x-2
3) 3(x - 2) - 14x = 2(3-) + 1
4) (x + 1)²+ 2x = x(x + 1) + 6
5) 3 - 4x(3 - 2x) = 8x² + x - 30
6) x²-x(5 - x) = 8
7) (x - 1)² - 36 = 0
8) (3x - 1)(4x - 3) + 2x(6x - 1) = 2(2x + 7)
9) (x - 2)² + 4(x - 3) =(x² + x - 3)
10) (x - 2)² – 2(x + 1) = (x - 1)(x - 2)
11) (x - 2)² + 3(x - 5) = x² + 3x - 3
12)(x - 3)² + (x + 3)² = 2 (x² +9)
13) (3x - 1)2 + (3x +1)² = 2(9x² + 4) + 1
14) (x - 1)(x - 2) + (2x + 1) = 5x²
cuoi nam hoc , truong thcs quang trung tang cho cac em hoc sinh 1 so tap viet .em thu nhat duoc 1 cuon va 1/11 so vo con lai. em thu 2 duoc 2 cuon va 1/11 so vo con lai . cho den em thu n dsuoc n cuon va 1/11 so vo con lai .hoi co bao nhieu em hoc sinh duoc nhan va tong so tap thuong la bao nhiu
Giai phương trình sau:
a,\(x^2+3x-10=0\) b,\(3x^2-7x+1=0\)
c,\(3x^2-7x+8=0\) d,\(4x^2-12x+9=0\)
e,\(3x^2+7x+2=0\) h,\(x^2-4x+1=0\)
i,\(2x^2-6x+1=0\) j, \(3x^2+4x-4=0\)
Bài 2: Giải các phương trình sau:
a) 7 – (2x + 4) = - (x + 4)
b) \(\frac{3x-1}{3}=\frac{2-x}{2}\)
c) \(\frac{2\left(3x+5\right)}{3}-\frac{x}{2}=5-\frac{3\left(x+1\right)}{4}\)
d) x2 – 4x + 4 = 9
e) \(\frac{x-1}{x+2}-\frac{x}{x-2}=\frac{5x-8}{x^2-4}\)
Giải các phương trình sau:
a) \(\frac{4}{x-1}-\frac{5}{x-2}=-3\)
b) \(3x-\frac{1}{x-2}=\frac{x-1}{2-x}\)
c) \(\frac{x+4}{x^2-3x+2}+\frac{x+1}{x^2-4x+3}=\frac{2x+5}{x^2-4x+3}\)
d) \(\frac{2}{x^2-4}-\frac{1}{x\left(x-2\right)}+\frac{x-4}{x\left(x+2\right)}=0\)
e) \(\frac{4x}{x^2+4x+3}-1=6\left(\frac{1}{x+3}-\frac{1}{2x+2}\right)\)
f) \(\frac{3}{4\left(x-5\right)}+\frac{15}{50-2x^2}=\frac{7}{6x+30}\)
g)\(\frac{1}{x-1}+\frac{2x^2-5}{x^3-1}=\frac{4}{x^2+x+1}\)
h) \(\frac{12x+1}{6x-2}-\frac{9x-5}{3x+1}=\frac{108x-36x^2-9}{4\left(9x^2-1\right)}\)
i) \(x+\frac{1}{x}=x^2+\frac{1}{x^2}\)
j) \(\frac{1}{x}+2=\left(\frac{1}{x}+2\right)\left(x^2+2\right)\)
k) \(\left(x+1+\frac{1}{x}\right)^2=\left(x-1-\frac{1}{x}\right)^2\)
a)\(x^4+\left(x-1\right)\left(3^{x^2}+2x-2\right)=0\)
b)\(\dfrac{x^2-3x+5}{x^2-4x+5}-\dfrac{x^2-5x+5}{x^2-6x+5}=\dfrac{-1}{4}\)
Phân tích các đa thức sau thành nhân tử :
1, A = x5 + 3x4 -x3 -x2 +13x +5
2, A1 = (x2+3x)2 - 2(x2 +3x) -8
3,A3 = (x2 +4x +10)2 -7x(x2+4x+11) +7