Tìm y : 2/9 + y = 1
Các bạn giúp mình nhé !
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) x/-2=-4/y=2/4
*x/-2=2/4=>4x=(-2)x2=>x=-1
*-4/y=2/4=>(-4)x4=2y=>y=-8
b)2/x=y/-3
=>xy=-6(câu này đề hơi lạ)
c) x+1/2=8/x+1
=>16=(x+1)(x+1)=>x^2+2x+1=16=>(x+1)^2=16=>(x+1)^2=4^2=>x+1=4=>x=3
48∈B(2x+1)
⇒48⋮2x+1
⇒2x+1∈Ư(48)
Ư(48)={1;2;3;4;6;8;12;16;24;48}
⇒x∈{0;1}
\(2x+1\inƯ\left(48\right)\)
\(\Leftrightarrow2x+1\in\left\{1;3\right\}\)
hay \(x\in\left\{0;1\right\}\)
\(A=x^2+x+1=x^2+2\cdot\dfrac{1}{2}\cdot x+\left(\dfrac{1}{2}\right)^2+\dfrac{3}{4}\)
\(A=\left(x+\dfrac{1}{2}\right)^2+\dfrac{3}{4}>0\)
A= x2 + x + 1
A = x2 + 2. \(\dfrac{1}{2}\). x + (\(\dfrac{1}{2}\))2 +\(\dfrac{3}{4}\)
A = ( x + \(\dfrac{1}{2}\))2 + \(\dfrac{3}{4}\) ≥ \(\dfrac{3}{4}\)
Vậy, x2 + x + 1>0 với mọi x
Đúng thì like giúp mik nha. Thx bạn
a: Ta có: \(\left(x+3\right)\left(x+4\right)\left(x+5\right)\left(x+6\right)+1\)
\(=\left(x^2+9x+18\right)\left(x^2+9x+20\right)+1\)
\(=\left(x^2+9x\right)^2+38\left(x^2+9x\right)+360+1\)
\(=\left(x^2+9x\right)^2+2\cdot\left(x^2+9x\right)\cdot19+19^2\)
\(=\left(x^2+9x+19\right)^2\)
b. \(x^2+y^2+2x+2y+2\left(x+1\right)\left(y+1\right)+2\)
\(=\left(x^2+2x+1\right)+2\left(x+1\right)\left(y+1\right)+\left(y^2+2y+1\right)\)
\(=\left(x+1\right)^2+2\left(x+1\right)\left(y+1\right)+\left(y+1\right)^2\)
\(=\left(x+1+y+1\right)^2=\left(x+y+2\right)^2\)
c. \(x^2-2x\left(y+2\right)+y^2+4y+4\)
\(=x^2-2x\left(y+2\right)+\left(y+2\right)^2\)
\(=\left(x-y-2\right)^2\)
d. \(x^2+2x\left(y+1\right)+y^2+2y+1\)
\(=x^2+2x\left(y+1\right)+\left(y+1\right)^2\)
\(=\left(x+y+1\right)^2\)
ta có :
y + y * 1/3 * 9/2 + y * 7/2
y * {1 +3/2 + 7/2 } =252
y * 6 = 252
y = 252 : 6
y = 42
\(=x^2\left(y+1\right)-\left(y+1\right)\)
=(y+1)(x-1)(x+1)
\(y+y\div0.25+y\div0,125+y\times2=15\)
\(y\times1+y\times4+y\times8+y\times2=15\)
\(y\times\left(1+4+8+2\right)=15\)
\(y\times15=15\)
\(y=15\div15\)
\(y=1\)
y + y : 0,25 + y : 0,125 + y x 2 = 15
y x 1 + y x 4 + y x 8 + y x 2 = 15
y x (1+4+8+2) = 15
y x 15 = 15
y = 15 : 15
y = 1
y =1-2/9=>y=7/9
2/9 + y = 1
y = 1 - 2/9
y = 7/9