ở câu hs tương tự có người trả lời giúp bn đấy
ở câu hs tương tự có người trả lời giúp bn đấy
Bài 1: Rút gọn
B= \(\dfrac{1}{2}\)+ (\(\dfrac{1}{2}\))\(^2\)+ (\(\dfrac{1}{2}\))\(^3\)+ (\(\dfrac{1}{2}\))\(^4\)+............+ (\(\dfrac{1}{2}\))\(^{98}\)+ (\(\dfrac{1}{2}\))\(^{99}\)
Bài 2: Tính
a) \(\dfrac{45^{10}.2^{10}}{75^{15}}\)
b) \(\dfrac{2^{15}.9^4}{6^3.8^3}\)
c)\(\dfrac{8^{10}+4^{10}}{8^4+4^{11}}\)
d) \(\dfrac{81^{11}.3^{17}}{27^{10}.9^{15}}\)
Bài 3: Tìm x, biết
a) (2\(x\) + 4)\(^2\) = \(\dfrac{1}{4}\)
b) (2\(x\) - 3)\(^2\) = 36
c) 5\(^{x+2}\) = 625
d) (\(x\) - 1) \(^{x+2}\) = (\(x\) - 1)\(^{x+4}\)
dạng : tỉ lệ thức
tìm x biết
a, \(\dfrac{x-2}{-1,2}=\dfrac{-5}{2}\)
b, \(\dfrac{-6}{x+1}=\dfrac{1,8}{9}\)
c, \(\dfrac{-3}{x}=\dfrac{x}{-12}\)
d, \(\dfrac{x-4}{x-1}=\dfrac{3}{5}\)
e,\(\dfrac{1,12}{-10}=\dfrac{11,2}{x}\)
a) \(\dfrac{x}{10}=\dfrac{y}{15}=\dfrac{z}{-21}\\ \) và x+y+z =92
b) \(\dfrac{x}{5}=\dfrac{y}{1}=\dfrac{z}{-2}\) và x+y-2z =160
c) 4x=3y=3z và x+y+z=1975
\(\dfrac{-10}{|2x-1|+10}\)
Giá trị nhỏ nhất
( x - 3,5 )2 + ( y - \(\dfrac{1}{10}\))4 ≤ 0
( 5x + 1 )2 = \(\dfrac{36}{49}\)
Giải hộ mình với mọi người.
Bài 59:Thay tỉ số giữa các số hữu tỉ bằng tỉ số giữa các số nguyên:
a)2,04:(-3,12);
b)(\(-1\dfrac{1}{2}\)):1,25;
c)4:\(5\dfrac{3}{4}\);
d)\(10\dfrac{3}{7}\):\(5\dfrac{3}{14}\).
Cho \(\dfrac{x}{a+2b+c}=\dfrac{y}{2a+b-c}=\dfrac{z}{4a-4b+c}\). Chứng minh rằng \(\dfrac{a}{x+2y+z}=\dfrac{b}{2x+y+z}=\dfrac{c}{4x-4y+z}\)
Tìm x:
1) \(\dfrac{1,2}{30}\)\(=\dfrac{3x+4}{50}\)
2) \(\dfrac{x-1}{x-5}\)\(=\dfrac{6}{7}\)
3) \(\dfrac{x-1}{3}\)\(=\dfrac{x+3}{5}\)
4) \(\dfrac{3}{7}\)\(=\dfrac{2x+1}{3x+5}\)
5) \(\dfrac{2x+3}{3x+1}\)\(=\dfrac{3}{4}\)
6) \(\dfrac{2x+3}{6}\)\(=\dfrac{7x-3}{15}\)
7) \(\dfrac{6x-5}{-7}\)\(=\dfrac{5x-3}{-5}\)
8) \(\dfrac{x+1}{x-2}\)\(=\dfrac{3}{4}\)
9) \(\dfrac{2x-3}{x+1}\)\(=\dfrac{4}{7}\)
10) \(\dfrac{2x+3}{7}\)\(=\dfrac{4x-1}{15}\)
11) \(\dfrac{2x+3}{24}\)\(=\dfrac{3x-1}{32}\)
12) \(\dfrac{2x+4}{7}\)\(=\dfrac{4x-2}{15}\)
13) \(\dfrac{11x-2}{7x+5}\)\(=\dfrac{11}{8}\)
14) \(\dfrac{12-7x}{-13}\)\(=\dfrac{4-3x}{-5}\)
15) \(\dfrac{52}{2x-1}\)\(=\dfrac{13}{30}\)
\(\dfrac{12^4."\left(-10^2\right)}{3^4.4^5.5^2}\)