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\(x,y\inℤ\)phải không?
Ta có:
\(\left(x^2y^2+4x^2+2y^2-4\right)-\left(x^2y^2+5x^2+y^2-3\right)=0\)\(=0\)
\(\Rightarrow x^2y^2+4x^2+2y^2-4-x^2y^2-5x^2-y^2+3=0\) (bỏ ngoặc đổi dấu)
\(\Rightarrow\left(x^2y^2-x^2y^2\right)+\left(4x^2-5x^2\right)+\left(2y^2-y^2\right)+\left(-4+3\right)=0\)
\(\Rightarrow0-x^2+y^2-1=0\)
\(\Rightarrow y^2-x^2=1\)
\(\Rightarrow\left(y-x\right)\left(y+x\right)=1\)
Vậy ta có
\(\left(y-x\right)=1;\left(y+x\right)=1\)\(\Rightarrow y=1;x=0\)
Hoặc \(\left(y-x\right)=-1;\left(y+x\right)=-1\)\(\Rightarrow y=-1;x=0\)
Vậy ...
(Không biết đúng không nữa, nếu thấy đúng thì t***k mik nhé!)
a) \(P+\left(4x^2-5xy-y^2\right)=5x^2+10xy-2y^2\)
\(P=5x^2+10xy-2y^2-4x^2+5xy+y^2\)
\(P=x^2+15xy-y^2\)
Vậy....
b) \(\left(2xy+y^2\right)-P=3x^2-6xy+y^2\)
\(P=2xy+y^2-3x^2+6xy-y^2\)
\(P=-3x^2+8xy\)
Vậy....
a) P + ( 4x2 - 5xy - y2 ) = 5x2 + 10xy - 2y2
<=> P = 5x2 + 10xy - 2y2 - ( 4x2 - 5xy - y2 )
= 5x2 + 10xy - 2y2 - 4x2 + 5xy + y2
= x2 + 15xy - y2
b) ( 2xy + y2 ) - P = 3x2 -6xy + y2
<=> P = ( 2xy + y2) - ( 3x2 - 6xy + y2 )
= 2xy + y2 - 3x2 + 6xy -y2
= 8xy - 3x2
Some shows are solid but dull; some shows are enjoyable but unsubstantial. This series is solid enough but manages to be one of the most energe, enjoyable viewing experiences I've ever had. I would not consider it the best anime ever made, but I might consider it the most flat-out enjoyable I've seen yet. The story is solid, the character designs quirky (obligatory pun) and memorable, the music phenomenal (courtesy of Yuki Hayashi), but there's just a special soul to this one that elevates it above its peers.
I was skepal at first as it seemed a somewhat cliche setup. In true shonen fashion, it spent a little while training up and then proceeded to completely obliterate my expectations. It took what I thought would be a tired story and breathed an overwhelming passion and life into it. It's filled to the brim with energy and heart, giving feels and frissons continually. It exemplifies the best of shonen: its messages of tenacity, crazy characters, thrilling battles, and sense of progression. It also avoids many of the problems typically associated with the genre, with (typically) better pacing and consistently spectacular animation. Studio Bones taking seasonal breaks between arcs to give them the time they deserve really gives this show an edge on its other cousins.
Oh, and studies show that watching series where characters you identify overcome and win is actually healthy for your brain. Turns out, that thrilling feeling you get when your favorite character does something awesome or pushes through is your brain releasing certain chemicals to match them. And I've never seen a show that so consistently make me wanna stand up and cheer. This might be the most motivational thing you'll ever watch
bạn tham khảo tại đây nha : Câu hỏi của Thanh Tâm - Toán lớp 8 - Học toán với OnlineMath
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Gọi số có 3 chữ số đó là abc ( Điều kiện: 0 < a < 10 ; -1 < b,c < 10)
Số ngược lại là cba ( Điều kiện: 0< c < 10 ; -1< b,a < 10)
abc - cba = 100a +10b +c - 100c - 10b - a = 99a +0b - 99c
Từ trên => 0b = 0 với mọi b
=> b= 0
Còn lại 99a - 99c =99.(a - c)
Để cho hiệu là số chính phương thì a - c là số chính phương
Để thỏa điều kiện trên thì a - c = 1;3;5;7 vì 1;3;5;7 là số chính phương
Làm tiếp nha!!
tu ke hinh :
a, xet tam giac ABD va tam giac HBD co : BD chung
goc ABD = goc HBD do BD la phan giac cua goc ABC (gt)
goc BAC = goc DHB = 90 do dau tu ma tim
=> tam giac ABD = tam giac HBD (ch - gn)
b,
+ AB _|_ AC do tam giac ABC vuong (gt) (1)
EI _|_ AC (gt) (2)
=> EI // AB (dl)
BI _|_ AB (gt) (3)
=> IB _|_ EI (dl) (4)
(1)(2)(3)(4) => EIBA la hinh chu nhat (dn)
co AB = EA (gt)
=> EIBA la hinh vuong (dn)
=> AB = AE = EI = IB (dn)
+ co tam giac ABD = tam giac HBD (Cau a) => BH = AB (dn)
=> AB = AE = EI = IB = BH (tcbc)
Cảm ưn nhưng mk cần câu c