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\(7x+4y⋮37\Leftrightarrow5\left(7x+4y\right)⋮37\Leftrightarrow35x+20y⋮37\)(dùng dấu 2 chiều vì \(\left(5,37\right)=1\))
Lại có \(74x+74y⋮37\)suy ra \(\left(74x+74y\right)-\left(35x+20y\right)⋮37\)
Điều đó có nghĩa là \(39x+54y⋮37\Leftrightarrow3\left(13x+18y\right)⋮37\)mà \(\left(3,37\right)=1\)nên \(13x+18y⋮37\)
Chúc bạn học tốt!
ta có
A=9(7x+4y) - 2(13x+18y)
A=63x+36y-26x-36y
A=x(63-26)-(36y-36y)
A=37x
=>A chia hết cho 37
mà 7x+4y chia hết cho 37=>9(7x+4y) chia hết cho 37
9(7x+4y) chia hết cho 37=>2(13x+18y)
mà 2 và 37 nguyên tố cùng nhau =>13x+18y chia hết cho 37
vậy 7x+4y chia hết cho 37 thì 13x+18y chia hết cho 37
gọi số đó là ab
ta có: ab=8x(a+b)
a x 10 + b =8 x a + 8 x b
a x 2=b x 7
vậy : ab =72
Gọi số đó là ab
Theo đề bài ta có:
ab = 8( a+ b )
10a + b = 8a + 8b
2a = 7b ( bớt mỗi bên đi 8a + b )
=> a = 7
b = 2
Vậy số cần tìm là 72
\(x\times4+\frac{1}{2}\times x=55,35\)
\(\Leftrightarrow x\times\left(4+\frac{1}{2}\right)=55,35\)
\(\Leftrightarrow x\times4,5=55,35\)
\(\Leftrightarrow x=55,35:4,5\)
\(\Leftrightarrow x=12,3\)
Vậy x= 12,3
x.4+1/2.x=55,35
x.(4+1/2)=55.35
x.9/2=55,35
x=55,35:9/2
x=12,3
vì là máy ko có dấu nhân nên thay dấu nhân là dấu chấm
1. I was given a notebook as a reward by my teacher.
2. Grapes are picked and then turned into wine.
3. I wasn't allowed to stay up late by my father.
4. Pencils aren't used in your Maths exam.
5. I was allowed to go picnic with my friends by my parents yesterday.
6. I wasn't told about his story.
7. This cake is made by me.
8. When I was a child, my leg was bitten by a dog.
9. Many social skills are needed when you enter the workplace.
1, I was given a notebook by my teacher as a reward
or A notebook was given to me by my teacher as a reward
2, Grapes are picked and wine is turned into
3, I am not allowed to stay up late by my father
4, pencils are not used in your maths
5, i was not allowed to go picnic with my friends by my parents yesterday
6, i was not told about his story
7, this cake was made by me
8, When I was a kid, my leg was bitten by a dog
9, many social kills are needed when the workplace is entered
1. Tom said he wanted to buy a pocket calculator for his father
2. My mother said she thought it wouldn't rain the next day
3. The nurse said the patient in that room hadn't obeyed doctor's orders
4. They said they couldn't meet me there either that day or the next day
5. Mr.Brown said their trip costed them two thousand dollars
6. He said to her that he couldn't find his hat anywhere in that room
7. My father said to them that his secretary was going to finish that job
1. Tom said: “I want to buy a pocket calculator for my father.”
.....................Tom said that he wanted to buy a pocket calculator for his father...........................................................................................
2. My mother said : “I think it won’t rain tomorrow.”
......................My mother said that she thought it wouldn't rain the following day...........................................................................................
3. The nurse said: “The patient in this room didn’t obey your orders, doctor.”
......................The nurse said to the doctor that the patient in that room hadn't obeyed his orders ...........................................................................................
4. They said : “We can’t meet you here either today or tomorrow.”
............They said that they couldn't meet me there either today or tomorrow(tham khảo c4).....................................................................................................
5. Mr. Brown said : “Our trip cost us two thousand dollars.”
.......................Mr. Brown said that their trip cost them two thousand dollars(tham khảo c5).........................................................................................
6. He said to her : “ I can’t find my hat anywhere in this room.”
..............He said to her that he couldn't find his hat anywhere in that room..................................................................................................
7. My father said to them : “My secretary is going to finish this job.”
My father said to them that his secretary was going to finish that job
a,220V-45W->cho biet hieu dien the dinh muc va cong suat dinh muc cua den khi hoat dong binh thuong
b,\(\Rightarrow\left\{{}\begin{matrix}Idm=\dfrac{Pdm}{Udm}=\dfrac{45}{220}=\dfrac{9}{44}A\\R=\dfrac{Udm^2}{Pdm}=\dfrac{220^2}{45}=\dfrac{9680}{9}\Omega\end{matrix}\right.\)
c,\(\Rightarrow Idm< Ic=0,35A\)=>co the dung loai cau chi nay
a: \(=\left(2a^2-3a^2-4a^2\right)+\left(-0.5a-2.5a+3a\right)+\left(5-4+7\right)=-5a^2+8\)
b: \(=\left(a^3-a^3\right)+\left(-2a^2-3a^2+4a^2\right)+\left(a+a-a\right)+\left(-5+4\right)=-a^2+a-1\)
c: \(=-b^4+3b^2-3b-1-b^3+1-3b^2+b^4-5+4b^3+5\)
\(=3b^3-3b\)
giúp mình voi , mọi ng ơi