Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a)\(\frac{x}{108}=\frac{-7}{9}.\frac{5}{6}\)
\(\frac{x}{108}=\frac{-35}{54}\)
\(\frac{x}{108}=\frac{-70}{108}\)
\(x=-70\)
b)
(x+5/95+1)+(x+6/94+1)+(x+7/93)+(x+8/92+1)+(x+9/91+1)=-5+5
x+100/95+x+100/94+x+100/93+x+100/92+x+100/91=0
(x+100)(1/95+1/94+1/93+1/92+1/91)=0
vì 1/95+1/94+1/93+1/92+1/91 khác 0
nên x+100=0
x=0+100
x=100
\(\frac{x}{108}=-\frac{7}{9}.\frac{5}{6}\)
\(\frac{x}{108}=-\frac{35}{54}\)
\(\Rightarrow x=\frac{108.-35}{54}=-70\)
bài dưới để làm tiếp cho
\(\frac{x+5}{95}\)+\(\frac{x+6}{94}\)+\(\frac{x+7}{93}\)+\(\frac{x+8}{92}\)+\(\frac{x+9}{91}\)= -5
\(\frac{x+5}{95}\)+\(\frac{x+6}{94}\)+\(\frac{x+7}{93}\)+\(\frac{x+8}{92}\)+\(\frac{x+9}{91}\)+ 5 = 0
\(\left(\frac{x+5}{95}+1\right)\)+ \(\left(\frac{x+6}{94}+1\right)+\left(\frac{x+7}{93}+1\right)+\left(\frac{x+8}{92}+1\right)+\left(\frac{x+9}{91}+1\right)=0\)
\(\frac{x+5+95}{95}+\frac{x+6+94}{94}+\frac{x+7+93}{93}+\frac{x+8+92}{92}+\frac{x+9+91}{91}=0\)
\(\frac{x+100}{95}+\frac{x+100}{94}+\frac{x+100}{93}+\frac{x+100}{92}+\frac{x+100}{91}\)
\(\left(x+100\right)\left(\frac{1}{95}+\frac{1}{94}+\frac{1}{93}+\frac{1}{92}+\frac{1}{91}\right)=0\)
SUY RA \(x+100=0\)
\(x=-100\)
VẬY: \(x=-100\)
Chúc bạn học tốt!
\(\frac{x-1}{95}+\frac{x-2}{94}=\frac{x-3}{93}+\frac{x-4}{92}\)
\(\Rightarrow\frac{x-1}{95}+\frac{x-2}{94}-\frac{x-3}{93}-\frac{x-4}{92}=0\)
\(\Rightarrow\left(\frac{x-1}{95}-1\right)+\left(\frac{x-2}{94}-1\right)-\left(\frac{x-3}{93}-1\right)-\left(\frac{x-4}{92}-1\right)=0\)
\(\Rightarrow\frac{x-96}{95}+\frac{x-96}{94}-\frac{x-96}{93}-\frac{x-96}{92}=0\)
\(\Rightarrow\left(x-96\right)\left(\frac{1}{95}+\frac{1}{94}-\frac{1}{93}-\frac{1}{92}\right)=0\)
\(\Rightarrow x-96=0\left(vì\frac{1}{95}+\frac{1}{94}-\frac{1}{93}-\frac{1}{92}\ne0\right)\)
\(=>x=96\)
Bài 1: so sánh
A = \(\frac56\) x \(\frac43\) x \(\frac{-12}{15}\)
A = \(\frac{5}{15}\) x \(-\frac{12}{6}\) x \(\frac43\)
A = -\(\frac13\) x 2 x \(\frac43\)
A = - \(\frac89\)
B = - \(\frac{4}{14}\) x \(\frac63\) x \(\frac{7}{18}\)
B = - \(\frac{4}{18}\) x ( \(\frac63\) x \(\frac{7}{14}\))
B = - \(\frac29\) x 1
B = - 2/9
8/9 > 2/9
- 8/9 < -2/9
Vậy A < B
Bài 1: So sánh:
H = (3/4 - 4/5) x (-20)
H = (15/20 - 16/20) x (-20)
H = -1/20 x (-20)
H = 1
K = (3/2 - 3/5) - 10/4
K = 30/20 - 12/20 - 50/20
K = 18/20 - 50/20
K = - 32/20
K = - 8/5 < 1
Vậy H > K
\(\frac{x+1}{99}+\frac{x+3}{97}+\frac{x+5}{95}=\frac{x+2}{98}+\frac{x+4}{96}+\frac{x+6}{94}\)
\(\left(\frac{x+1}{99}+1\right)+\left(\frac{x+3}{97}+1\right)+\left(\frac{x+5}{95}+1\right)=\left(\frac{x+2}{98}+1\right)+\left(\frac{x+4}{96}+1\right)+\left(\frac{x+6}{94}+1\right)\)
\(\left(\frac{x+1}{99}+\frac{99}{99}\right)+\left(\frac{x+3}{97}+\frac{97}{97}\right)+\left(\frac{x+5}{95}+\frac{95}{95}\right)=\left(\frac{x+2}{98}+\frac{98}{98}\right)+\left(\frac{x+4}{96}+\frac{96}{96}\right)+\left(\frac{\left(x+6\right)}{94}+\frac{94}{94}\right)\)
\(\frac{x+100}{99}+\frac{x+100}{97}+\frac{x+100}{95}=\frac{x+100}{92}+\frac{x+100}{94}+\frac{x+100}{96}\)
\(\frac{x+100}{99}+\frac{x+100}{97}+\frac{x+100}{95}-\frac{x+100}{92}-\frac{x+100}{94}-\frac{x+100}{96}=0\)
\(\left(x+100\right).\left(\frac{1}{99}+\frac{1}{97}+\frac{1}{95}-\frac{1}{92}-\frac{1}{94}-\frac{1}{96}\right)=0\)
\(Mà\) \(\frac{1}{99}+\frac{1}{97}+\frac{1}{95}-\frac{1}{92}-\frac{1}{94}-\frac{1}{96}\ne0\)
Nên x+ 100 = 0
x = 0 - 100 = -100
Vậy x= -100
cộng 1 vào mỗi tỉ số,ta được:
\(\left(\frac{x+1}{99}+1\right)+\left(\frac{x+3}{97}+1\right)+\left(\frac{x+5}{95}+1\right)=\left(\frac{x+2}{98}+1\right)+\left(\frac{x+4}{96}+1\right)+\left(\frac{x+6}{94}+1\right)\)\(\Rightarrow\frac{x+1+99}{99}+\frac{x+3+97}{97}+\frac{x+5+95}{95}=\frac{x+2+98}{98}+\frac{x+4+96}{96}+\frac{x+6+94}{94}\)
\(\Rightarrow\frac{x+100}{99}+\frac{x+100}{97}+\frac{x+100}{95}=\frac{x+100}{98}+\frac{x+100}{96}+\frac{x+100}{94}\)
\(\Rightarrow\frac{x+100}{99}+\frac{x+100}{97}+\frac{x+100}{95}-\frac{x+100}{98}-\frac{x+100}{96}-\frac{x+100}{94}=0\)
\(\Rightarrow\left(x+100\right)\left(\frac{1}{99}+\frac{1}{97}+\frac{1}{95}-\frac{1}{98}-\frac{1}{96}-\frac{1}{94}\right)\)
Vì \(\frac{1}{99}+\frac{1}{97}+\frac{1}{95}-\frac{1}{98}-\frac{1}{96}-\frac{1}{94}\ne0\)
=>x+100=0
=>x=-100
Vậy x=-100
\(\Rightarrow\left(\frac{x+2}{98}+1\right)+\left(\frac{x+4}{96}+1\right)=\left(\frac{x+6}{94}+1\right)+\left(\frac{x+8}{92}+1\right)\)
\(\Rightarrow\frac{x+100}{98}+\frac{x+100}{96}=\frac{x+100}{94}+\frac{x+100}{92}\)
\(\Rightarrow\frac{x+100}{98}+\frac{x+100}{96}-\frac{x+100}{94}-\frac{x+100}{92}=0\)
\(\Rightarrow\left(x+100\right)\left(\frac{1}{98}+\frac{1}{96}-\frac{1}{94}-\frac{1}{92}\right)=0\)
\(\Rightarrow x+100=0\)
\(\Rightarrow x=0-100=-100\)
x=-100
\(\frac{x+5}{95}+\frac{x+6}{94}+\frac{x+7}{93}+\frac{x+8}{92}+\frac{x+9}{91}=-5\)
\(\left(\frac{x+5}{95}+1\right)+\left(\frac{x+6}{94}+1\right)+\left(\frac{x+7}{93}+1\right)+\left(\frac{x+8}{92}+1\right)+\left(\frac{x+9}{91}+1\right)=-5+5=0\)
x=100
k hộ với
\(\frac{x+100}{95}+\frac{x+100}{94}+\frac{x+100}{93}+\frac{x+100}{92}+\frac{x+100}{91}\)
\(\left(x+100\right)\left(\frac{1}{95}+\frac{1}{94}+\frac{1}{93}+\frac{1}{92}+\frac{1}{91}\right)=0\)
\(x+100=0\)
\(\Rightarrow x=-100\)