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a) \(P\left(x\right)=2+5x^2-3x^3+4x^2-2x-x^3+6x^5\)
\(=6x^5-4x^3+9x^2-2x+2\)
b) \(P\left(1\right)=6\cdot1^5-4\cdot1^3+9\cdot1^2-2\cdot1+2\)
\(=6-4+9-2+2\)
\(=11\)
dù bạn đăng nhầm nhưng mình vẫn trả lời nha !
a) f(x)- g(x)+h(x) = (x3-2x2+3x+1)-(x3+x-1)+(2x2-1)
f(x)- g(x)+h(x) = x3-2x2+3x+1- x3-x+1+2x2-1
f(x)- g(x)+h(x)= (x3-x3) +(2x2-2x2) +(3x-x)+(1+1-1)
f(x)- g(x)+h(x) = 0+0+2x+1
f(x)- g(x)+h(x) = 2x+1
b) Xét f(x)- g(x)+h(x)=0
Suy ra: 2x+1=0
2x= -1
x = - \(\dfrac{1}{2}\)
Ta có : 2x = 5y \(\Rightarrow\frac{x}{5}=\frac{y}{2}\Rightarrow\frac{x^2}{25}=\frac{y^2}{4}\)
Áp dụng t/c của dãy tỉ số bằng nhau, ta có :
\(\frac{x^2}{25}=\frac{y^2}{4}=\frac{x^2+y^2}{25+4}=\frac{133}{29}\)
Suy ra :
+) \(\frac{x^2}{25}=\frac{133}{29}\Leftrightarrow x^2=\frac{3325}{29}\Leftrightarrow x=\sqrt{\frac{3325}{29}}\approx10,7\)
+)\(\frac{y^2}{4}=\frac{133}{29}\Leftrightarrow y^2=\frac{532}{29}\Leftrightarrow y=\sqrt{\frac{532}{29}}\approx4,3\)
Vậy \(x\approx10,7;y\approx4,3\)
Thay x= 1 vào f(x), có:
f(x) = 14+2.13-2.12-6.1-5
f(x) = 1 + 2 - 2 - 6 - 5
f(x) = -10
=> x = 1 không phải là nghiệm của f(x)
Thay x = - 1 vào f(x); có:
f(x) = (-1)4+2.(-1)3-2.(-1)2-6.(-1) - 5
f(x) = 1 - 2 - 2 + 6 - 5
f(x) = -2
=> x = -1 không phải là nghiệm của f(x)
...
rùi bn lm típ nha! mk chỉ bk cách này thoy!
The Rio de Janeiro Carnival - Rio de Janeiro, Brazil Brazil's most popular and festive holiday is Canival. In fact, many people (1)....................Canival one of the world's biggest celebrations. Each spring, on the Saturday before AshWenesday, the street of Brazil 's largest city, Rio de Janeiro, come alive(2)...................wild parties, festivals and glamorous dances. The Sanba School Parade is the highlight of the(3)...................event. About 3,000 performers, in colourful costumes enbellished with feathers, beads and thousands of sequins, dance down the parade route into the Sambadrome - a dance stadium(4)....................built for the event. Judges award a(5)....................to the most spectacular group of dancers.
1. A. consider B. regard C. believe D. hope
2. A. of B. in C. with D. at
3. A. four days B. four - days C. fourth day D. four - day
4. A. build B. built C. to build D. building
5. A. prize B. price C. respect D. result
The Rio de Janeiro Carnival - Rio de Janeiro, Brazil Brazil's most popular and festive holiday is Canival. In fact, many people(1)....................Canival one of the world's biggest celebrations. Each spring, on the Saturday before AshWenesday, the street of Brazil 's largest city, Rio de Janeiro, come alive(2)...................wild parties, festivals and glamorous dances. The Sanba School Parade is the highlight of the(3)...................event. About 3,000 performers, in colourful costumes enbellished with feathers, beads and thousands of sequins, dance down the parade route into the Sambadrome - a dance stadium(4)....................built for the event. Judges award a(5)....................to the most spectacular group of dancers.
1. A. consider B. regard C. believe D. hope
2. A. of B. in C. with D. at
3. A. four days B. four - days C. fourth day D. four - day
4. A. build B. built C. to build D. building
5. A. prize B. price C. respect D. result