\(\Leftrightarrow\dfrac{x+100}{86}+\dfrac{x+100}{85}+\dfrac{x+100}{84}+\dfrac{x+100}{83}=0\)

=>x+100=0

hay x=-100

86 x 0,75 + 14 x \(\frac{3}{4}\)

= 86 x 0,75 + 14 x 0,75

= (86 + 14) x 0,75

= 100 x 0,75

= 75

k mk nha !

86 x 0.75 + 14 x \(\frac{3}{4}\)

= 64.5 + 10.5

= 75

 (1374 x 57 + 687 x 86) : (26 x 13 + 74 x 14) =

(1374 x 57 + 1374 x 43) : (26 x 13 + 74 x 13 + 74)

(1374 x 100) : (13 x 100 + 74) =

137400 : 1374 = 100

tic mk nhé

(124*237+152): (870+235*122)

Ai Giải hộ mình với

mik thắc mắc tại sao 26 x 13 + 74 x 14  lại đc viết thành 26 x 13  + 74 x 13 + 74 vậy 

14x6=

\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+14}{83}+\frac{x+116}{4}=0\)

\(\frac{x+14}{86}+1+\frac{x+15}{85}+1+\frac{x+16}{84}+1+\frac{x+14}{83}+1+\frac{x+116}{4}-4=0\)

\(\frac{x+14+86}{86}+\frac{x+15+85}{85}+\frac{x+16+84}{84}+\frac{x+14+83}{83}+\frac{x+116-16}{4}=0\)

\(\frac{x+100}{86}+\frac{x+100}{85}+\frac{x+100}{84}+\frac{x+100}{83}+\frac{x+100}{4}=0\)

\(\left(x+100\right)\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)=0\)

Vì \(\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)\ne0\)

\(\Rightarrow x+100=0\)

\(\Rightarrow x=-100\)

Vậy........

\(a,\left(4x-8\right)\left(12-y\right)=0\)

\(\Rightarrow\hept{\begin{cases}4x-8=0\\12-y=0\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}4x=8\\y=12\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}x=2\\y=12\end{cases}}\)

\(b,\left(2x-12\right)-14=86\)

\(\Rightarrow2\left(x-6\right)=86+14=100\)

\(\Rightarrow x-6=50\)

\(\Rightarrow x=50+6=56\)

\(c,\left(127-x\right)-17=43\)

\(\Rightarrow127-x=43+17=60\)

\(\Rightarrow x=127-60=67\)

\(\left(4x-8\right)\left(12-y\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}4x-8=0\\12-y=0\end{cases}\Leftrightarrow\orbr{\begin{cases}4x=8\\y=12-0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=2\\y=12\end{cases}}}\)

Vậy x = 2 hoặc y = 12

\(\left(2x-12\right)-14=86\)

\(\Leftrightarrow2x-12=100\)

\(\Leftrightarrow2x=112\)

\(\Leftrightarrow x=56\)

Vậy x = 56

\(\left(127-x\right)-17=43\)

\(\Leftrightarrow127-x=60\)

\(\Leftrightarrow x=127-60\)

\(\Leftrightarrow x=67\)

Vậy x = 67

\(\left(4x-8\right)\left(12-y\right)=0\)

\(\Rightarrow\orbr{\begin{cases}4x-8=0\\12-y=0\end{cases}\Rightarrow\orbr{\begin{cases}4x=0+8\\y=12-0\end{cases}}}\)

\(\Rightarrow\orbr{\begin{cases}4x=8\\y=12\end{cases}\Rightarrow\orbr{\begin{cases}x=8\div4\\y=12\end{cases}\Rightarrow}\orbr{\begin{cases}x=2\\y=12\end{cases}}}\)

Vậy x = 2 hoặc y = 12

(2x - 12) - 14 = 86

=> 2x - 12 = 86 + 14

=> 2x - 12 = 100

=> 2x = 100 + 12

=> 2x = 112

=> x = 112 : 2

=> x = 56

Vậy x = 56

(127 - x) - 17 = 43

=> 127 - x = 43 + 17

=> 127 - x = 60

=> x = 127 - 60

=> x = 67

Vậy x = 67

86+86+14+14+56+44

=300

chuc ban hok tot

86+86+14+14+56+44=2664

mik nha

= 86+14+86+14+56+44

= 100+100+100

=300

lần sau đừng đặng câu hỏi như này nữa nha!!

ta có 42-(14+86) = 72 - (5-x) <=> 42 - 100 = 72 - 5 +x <=> -142 = 67 + x <=> x= -209

Vậy x=-209

Ta có : 42-(14+86) = 72 - (5-x) \(\Leftrightarrow\)42-100 = 72-5+x\(\Leftrightarrow\)-142 = 67+x \(\Leftrightarrow\)x = -209

Vậy x = -209