x:(1245+64-35+26)=100

x:1300=100

x=130000

b,x*(236-36)=2000

x*200=2000

x=2000:200

x=10

**** nha bạn phương Chi

a/

1245:x+64:x-35:x+26:x=100

=>(1245+64-35+26):x=100

=>1300:x=100

=>x=1300:100

=>x=13

236*x-x*36=2000

=>x*(236-36)=2000

=>x*200=2000

=>x=2000:200

=>x=10

a) 1245 : x + 64 : x - 35 : x + 26 : x = 100

(1245 + 64 - 35 + 26) : x = 100

1300 : x = 100

x = 1300 : 100 

x = 13

b) 236 * x - x * 36 = 2000

(236 - 36) * x = 2000

200 * x = 2000

x = 2000 : 200 = 10

bạn lên học 24/7 hỏi nha

\(\frac{2}{\left(x+3\right)\left(x+1\right)}+\frac{2}{\left(x+3\right)\left(x+5\right)}+\frac{2}{\left(x+5\right)\left(x+7\right)}=\frac{2}{9}\)

\(\Rightarrow\frac{2}{x+1}-\frac{2}{x+3}+\frac{2}{x+3}-\frac{2}{x+5}+\frac{2}{x+5}-\frac{2}{x+7}=\frac{2}{9}\)

\(\frac{2}{x+1}-\frac{2}{x+7}=\frac{2}{9}\\ \Rightarrow\frac{2x+14-2x-2}{\left(x+1\right)\left(x+7\right)}=\frac{2}{9}\\ \Rightarrow\frac{12}{\left(x+1\right)\left(x+7\right)}=\frac{2}{9}=\frac{12}{54}\)

\(\Rightarrow\left(x+1\right)\left(x+7\right)=54\\ \Rightarrow x^2+8x-54=0\Rightarrow x=-4\pm\sqrt{70}\)

chết oy mk nhầm nha

\(\Rightarrow\frac{2}{\left(x+1\right)\left(x+3\right)}+\frac{2}{\left(x+3\right)\left(x+5\right)}+\frac{2}{\left(x+5\right)\left(x+7\right)}=\frac{2}{9}\Leftrightarrow\frac{1}{x+1}-\frac{1}{x+7}=\frac{2}{9}\)

\(\Rightarrow\frac{6}{\left(x+1\right)\left(x+7\right)}=\frac{2}{9}=\frac{6}{27}\\ \Rightarrow\left(x+1\right)\left(x+7\right)=27\)

\(\Rightarrow x^2+8x-20=0\Rightarrow\left(x-2\right)\left(x+10\right)=0\Rightarrow\orbr{\begin{cases}x=2\\x=-10\end{cases}}\)

sorry bạn nha mk nhầm xíu

\(\frac{1}{x^2+4x+3}=\frac{1}{\left(x+1\right)\left(x+3\right)}=\frac{1}{2}\left(\frac{1}{x+1}-\frac{1}{x+3}\right)\)

\(\frac{1}{x^2+8x+15}=\frac{1}{\left(x+3\right)\left(x+5\right)}=\frac{1}{2}\left(\frac{1}{x+3}-\frac{1}{x+5}\right)\)

...

Cộng theo vế các hạng tử sẽ bị triệt tiêu

\(\Leftrightarrow\frac{1}{x^2+16x+63}+\frac{1}{x^2+12x+35}+\frac{1}{x^2+8x+15}+\frac{1}{x^2+4x+3}=\frac{1}{5}\)

\(\Rightarrow\frac{1}{x^2+16x+63}+\frac{1}{x^2+12x+35}+\frac{1}{x^2+8x+15}+\frac{1}{x^2+4x+3}-\frac{1}{5}=0\)

\(\Leftrightarrow-\frac{x^2+10x-11}{5\left(x+1\right)\left(x+9\right)}=0\)

=>x²+10x-11=0

10²-(-4(1.11))=144

\(\Rightarrow x_{1,2}=\frac{-b\pm\sqrt{\Delta}}{2a}=\frac{-10\pm\sqrt{144}}{2}\)

x₁=[(-10)+12]:2=1

x₂=[(-10)-12]:2=-11

tổng nghiệm của pt là 1+(-11)=-10

@Thắng: sao bạn không dùng Viet luôn?

1085.39830508

256154 : 236 = 1085,398305

k mik nha , mik k lại !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

256154 : 236 = 1085 ( dư 94 )

ủng hộ nha

\(\frac{8x+4}{4x+5}=\frac{8x+10-6}{4x+5}=\frac{2\left(4x+5\right)-6}{4x+5}=\frac{2\left(4x+5\right)}{4x+5}-\frac{6}{4x+5}=2-\frac{6}{4x+5}\)

De 8x + 4/4x + 5 dat gia tri lon nhat <=> 2 - 6/4x + 5 dat gia tri lon nhat <=> 6/4x + 5 dat gia tri lon nhat

=> 4x + 5 dat gia tri nho nhat  (4x + 5 > 0)

=> 4x + 5 = 1 => x = -1

Khi do gia tri lon nhat cua \(\frac{8x+4}{4x+5}=\frac{8.\left(-1\right)+4}{4.\left(-1\right)+5}=\frac{-8+4}{-4+5}=\frac{-4}{1}=-4\)

Vay gia tri lon nhat cua \(\frac{8x+4}{4x+5}=-4\)khi x = -1