x - 45 = 55
x+45=45-45+55:55
x+45=45-45+55:55
x+45=0+1
x+45=1
x=1-45
x=-44
k nhé mk vừa k bn rùi
x + 45 = 45 - 45 + 55 : 55
x + 45 = 45 - 45 + 1
x + 45 = 0 + 1
x + 45 = 1
x = 1 - 45
x = -44
( 800 + 55 ) x 45 + ( 900 - 45 ) x 55
= 855x45+ 855x55
= 855x( 45+55)
=855x100
=85500
55 x 45 + 55 x 55
55 x 45 + 55 x 55
= 55 x ( 45 + 55 )
= 55 x 100
= 5500
55 x 45 + 55 x 55
= 55 x (45 + 55)
= 55 x 100
= 5500 nha
Nguyễn Hữu Triết\(\dfrac{x-45}{55}+\dfrac{x-47}{53}=\dfrac{x-55}{45}+\dfrac{x-53}{47}\)
giải phương trình trên
\(\dfrac{x-45}{55}+\dfrac{x-47}{53}=\dfrac{x-55}{45}+\dfrac{x-53}{47}\)
\(\Leftrightarrow\left(\dfrac{x-45}{55}-1\right)+\left(\dfrac{x-47}{53}-1\right)=\left(\dfrac{x-55}{45}-1\right)+\left(\dfrac{x-53}{47}-1\right)\)
\(\Leftrightarrow\dfrac{x-100}{55}+\dfrac{x-100}{53}=\dfrac{x-100}{45}+\dfrac{x-100}{47}\)
\(\Leftrightarrow\dfrac{x-100}{55}+\dfrac{x-100}{53}-\dfrac{x-100}{45}-\dfrac{x-100}{47}=0\)
\(\Leftrightarrow\left(x-100\right)\left(\dfrac{1}{55}+\dfrac{1}{53}-\dfrac{1}{45}-\dfrac{1}{47}\right)=0\)
Do \(\dfrac{1}{55}+\dfrac{1}{53}-\dfrac{1}{45}-\dfrac{1}{47}\ne0\) nên x - 100 = 0 <=> x = 100
Tính bằng cách hợp lý:
(900 - 45) x 45 + (800 + 55) x 55
(900-45)x45+(800+55)x55
=855x45+855x55
=855x(45+55)
=855x100
=85500
( 900 - 45 ) x 45 + ( 800 + 55 ) x 55
= 855 x 45 + 855 x 55
= 855 x ( 45 + 55 )
= 855 x 100
= 85500
45 x 45 + 45 x 55
Số cần tìm là:
45 x (45+55)=4500
Đáp số: 4500
45x(45+55)=45x100=4500
k cho mk nhé
tự đặt câu hỏi rồi trả lời thì làm làm cái gì
X:2+250*4=55*61+69*55-45*37-93*45
\(x:2+250.4=55.61+69.55-45.37-93.45\)
\(\Leftrightarrow x:2+1000=55\left(61+69\right)-45\left(37+93\right)\)
\(\Leftrightarrow x:2+1000=55.130-45.130\)
\(\Leftrightarrow x:2+1000=130\left(55-45\right)\)
\(\Leftrightarrow x:2+1000=130.10\)
\(\Leftrightarrow x:2+1000=1300\)
\(\Leftrightarrow x:2=1300-1000=300\)
\(\Leftrightarrow x=300.2=600\)
Vậy \(x=600\)
X:2+250*4=55*61+69*55-45*37-93*45
X:2+250*4=(55*61+69*55)-(45*37+93*45)
X:2+1000=55*(61+69)-45*(37+93)
X:2+1000=55*130-45*130
X:2+1000=(55-45)*130
X:2+1000=10*130
X:2+1000=1300
X:2=1300-1000
X:2=300
X=300*2
X=600
Vậy X = 600
tính nhanh
45 x ( 55 + 117 ) + 55 x ( 117 - 45 )
45 x ( 55 + 117 ) + 55 x ( 117 - 45 )
= (45 x 55 - 45 x 55) + (45 + 55) x 117
= 0 + 100 x 117 = 11700
\(45\times\left(55+117\right)+55\times\left(117-45\right)\)
\(=45\times55+45\times117+55\times117-55\times45\)
\(=\left(45\times55-45\times55\right)+45\times117+55\times117\)
\(=45\times117+55\times117\)
\(=117\times\left(45+55\right)\)
\(=117\times100\)
\(=11700\)
giải pt:
X-45/55 + X-47/53 = X-55/45 +X-53/47
các bn giúp mik vs
<=>x-45/55 -1 + x-47/53 -1=x-55/45 -1 + x-53/47-1
<=>x-100/55 + x-100/53 = x-100/45 + x-100/47
<=>(x-100)(1/55 + 1/53 - 1/45 - 1/47 )=0
vi (1/55 + 1/53 - 1/45 - 1/47 ) luon khac 0 nen x-100=0 <=>x=100
Giải phương trình sau
\(\frac{x-45}{55}+\frac{x-47}{53}=\frac{x-55}{45}+\frac{x-53}{47}\)
\(\frac{x-45}{55}+\frac{x-47}{53}=\frac{x-55}{45}+\frac{x-53}{47}\)
\(\Rightarrow\frac{x-45}{55}-1+\frac{x-47}{53}-1=\frac{x-55}{45}-1+\frac{x-53}{47}-1\)
\(\Rightarrow\frac{x-100}{55}+\frac{x-100}{53}=\frac{x-100}{45}+\frac{x-100}{47}\)
\(\Rightarrow\frac{x-100}{55}+\frac{x-100}{53}-\frac{x-100}{45}-\frac{x-100}{47}=0\)
\(\Rightarrow\left(x-100\right)\left(\frac{1}{55}+\frac{1}{53}-\frac{1}{45}-\frac{1}{47}\right)=0\)
\(\Rightarrow x-100=0\).Do \(\frac{1}{55}+\frac{1}{53}-\frac{1}{45}-\frac{1}{47}\ne0\)
\(\Rightarrow x=100\)
\(\frac{x-45}{55}+\frac{x-47}{53}=\frac{x-55}{45}+\frac{x-53}{47}\)
\(\frac{x-45}{55}-1-\frac{x-47}{53}-1=\frac{x-55}{45}-1+\frac{x-53}{47}-1\)
\(\frac{x-100}{55}+\frac{x-100}{53}=\frac{x-100}{45}+\frac{x-100}{47}\)
\(\frac{x-100}{55}+\frac{x-100}{53}-\frac{x-100}{45}-\frac{x-100}{47}=0\)
(x-100)(\(\frac{1}{55}+\frac{1}{53}-\frac{1}{45}-\frac{1}{47}=0\)
-> x-100 = 0 -> x = 100
mà \(\frac{1}{55}+\frac{1}{53}-\frac{1}{45}-\frac{1}{47}\) khác 0
Vậy x = 100