a) 35 × x = 805

x = 805 : 35

x = 23

b) x : 37 + 1238 = 1644

x : 37 = 1644 - 1238

x : 37 = 406

x = 406 × 37

x = 15022

a) \(35\times x=805\)

\(x\) = 805 : 35

\(x\) = 23

b) \(x\div37+1238=\) \(1644\)

x : 37 = 1644 - 1238

x : 37 = 406

x = 406 x 37

x = 15022

x=79

nên x+1=80

\(P\left(x\right)=-80x^6+80x^5-80x^4+...+80x+15\)

\(=-x^6\left(x+1\right)+x^5\left(x+1\right)-x^4\left(x+1\right)+...+x\left(x+1\right)+15\)

\(=-x^7-x^6+x^6+x^5-x^5-x^4+...+x^2+x+15\)

\(=-x^7+x+15\)

\(=-79^7+79+15\)

\(=-79^7+94\)

\(x=79\Leftrightarrow x+1=80\\ \Leftrightarrow P\left(x\right)=-\left(x+1\right)x^6+\left(x+1\right)x^5-\left(x+1\right)x^4+...+\left(x+1\right)x+15\\ P\left(x\right)=-x^7-x^6+x^6+x^5-x^5-x^4+...+x^2+x+15\\ P\left(x\right)=-x^7+x+15=-79^7+94\)

20.11x194+20.11x805+20.11

=20.11x(194+805+1)

=20.11x1000=20110

X x 3.4 +X x1.2=23

X x( 3.4+1.2)=23

X x 4.6=23

X=23 :4.6=5

* \(20,11.194+20,11.805+20,11\)

\(=20,11.\left(194+805+1\right)\)

\(=20,11.1000\)

\(=20110\)

* \(x.3,4+x.1,2=23\)

\(\Leftrightarrow x.\left(3,4+1,2\right)=23\)

\(\Leftrightarrow x.4,6=23\)

\(\Leftrightarrow x=23:4,6\)

\(\Leftrightarrow x=5\)

(Nhớ k cho mình với nha!)

=20.11(194+805+1)=20.11*1000=20110

X(3.4+1.2)=23

X*23/5=23

X=5

50 x 125 x 2 x 8 x 805

(50 . 2).(125. 8). 805

100. 1000 . 805

100000. 805

80500000

chúc bạn học tốt!!!

50 x 125 x 2 x 8 x 805

= ( 50 x 2 ) x ( 125 x 8 ) x 805

= 100 x 1000 x 805

= 100 000 x 805

= 80 500 000

_HT_

50x125x2x8x805=50x2x125x8x805=100x1000x805=80500000          ok em nhé

( y xy) x 8 = 805 - 15 : 3

( y xy) x 8 = 800

(y xy) x 8 = 800 : 8

( y xy) x 8 = 100

nhung chi co 50 x 2 = 100.

vay y = 50.

y=50 nha ban

duyet nha

y = 10 nha bạn

\(\frac{1}{9x10}\)\(+\frac{1}{10x11}\)\(+\frac{1}{11x12}\)\(+.....\)\(+\frac{1}{805x806}\)

\(=\frac{1}{9}\)\(-\frac{1}{10}\)\(+\frac{1}{10}\)\(-\frac{1}{11}\)\(+\frac{1}{11}\)\(-\frac{1}{12}\)\(+.....\frac{1}{805}\)\(-\frac{1}{806}\)

\(=\frac{1}{9}\)\(-\frac{1}{806}\)

\(=\frac{797}{7254}\)

64 x X + X + 32 x X + X x 3 = 805

(64+1+32+3) x X = 805

100 x X = 805

X = 805: 100

X = 8,05

2008 x 68 + 32 x 2008

= 2008 x (68 +32)

= 2008x100= 200800

64 x X + X + 32 x X + X x 3 = 805

X x ( 64 + 1 + 32 + 3 ) = 805

X x ( 65 + 35 ) = 805

X x 100 = 805

X = 805 : 100

X = 8,05

2008 x 68 + 32 x 2008

= 2008 x ( 68 + 32 )

= 2008 x 100

= 200800

Cài này tớ giải rồi nhưng rảnh làm lại lần nữa:d

\(329.x=329:x\) 

\(\Leftrightarrow329.x=329.\frac{1}{x}\) 

\(\Leftrightarrow329.x-329.\frac{1}{x}=0\) 

\(\Leftrightarrow329.\left(x-\frac{1}{x}\right)=0\) 

\(\Leftrightarrow x-\frac{1}{x}=0\) 

\(\Leftrightarrow\frac{x^2-1}{x}=0\) 

\(\Rightarrow\left(x-1\right)\left(x+1\right)=0\) 

\(\Rightarrow\orbr{\begin{cases}x-1=0\\x+1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=1\\x=-1\end{cases}}\) 

Chúc bạn học tốt!

X = 1 nha

=1

hihi

a) 23 075 + 156 934  = 180 009

b)  45 344 : 26     = 1744

c)  805 372 – 32 821 = 772551

d)  128 x 693 = 88 704

478:25