(3|x|+15).(16-x2).(x3+125)=0 GIÚP MÌNH VỚI , GẤP NHÉ , THANK YOU
Tính nhanh :
a)(2x - 16)7 = 128
b) x3 . x2 = 28 : 23
c) 3 x - 3 - 32 = 2 . 32
MỌI NGƯỜI GIẢI GIÚP MÌNH NHÉ ! CẢM ƠN MỌI NGƯỜI !
\(a,\left(2x-16\right)^7=128\\ \Rightarrow\left(2x-16\right)^7=2^7\\ \Rightarrow2x-16=2\\ \Rightarrow2x=18\\ \Rightarrow x=9\\ b,x^3.x^2=2^8:2^3\\ \Rightarrow x^5=2^5\\ \Rightarrow x=5\\ c,3^{x-3}-3^2=2.3^2\\ \Rightarrow3^{x-3}-9=18\\ \Rightarrow3^{x-3}=27\\ \Rightarrow3^{x-3}=3^3\\ \Rightarrow x-3=3\\ \Rightarrow x=6\)
Thực hiện phép tính|-1.25|+8/5×(-1/4)^2-√81/16÷15/16 A.1,05. B.-1.05. C.105/100. D.-21/20,giúp mình với ,mình đang cần gấp ,chính xác nhé ,thank mn
2x-15=x+11-(-16)
Giúp mình với ai trả lời m tick cho thank you
2.x-15=x+11-(-16)
2.x-15=x+27
\(2x-15=x+11-\left(-16\right)\)
\(\Rightarrow2x-x=11+16+15\)
\(\Rightarrow x=27+15\)
\(\Rightarrow x=42\)
Vậy..................
2x - 15 = x +11- ( -16 )
2x - 15 = x + 27
2x - x = 27 - 15
x = 12
cho x,y thoả mãn : x3+2y2-4y +3=0
x2+x2y2-2y=0
tính Q=x2+y2
nhờ mn giúp mk vs ạ
mình đang cần gấp
\(\Leftrightarrow\left\{{}\begin{matrix}x^3+2y^2-4y+3=0\\2x^2+2x^2y^2-4y=0\left(1\right)\end{matrix}\right.\Rightarrow}x^3+2y^2-4y-2x^2-2x^2y^2+4y=0\Rightarrow x^3+1-2x^2y^2+2y^2-2x^2+2=0\Rightarrow\left(x+1\right)\left(x^2-x+1\right)-2y^2\left(x-1\right)\left(x+1\right)-2\left(x-1\right)\left(x+1\right)=0\Rightarrow\left(x+1\right)\left(x^2-x+1-2xy^2+2y^2-2x+2\right)=0\Rightarrow x=-1\)Thay x=-1 vào (1) ta được y2-2y+1=0⇒ (y-1)2=0⇒y-1=0⇒y=1
Do đó Q=x2+y2=(-1)2+12=2
cho:x1+x2+x3+...+x20+x21=0.tinh x21
x1+x2=x3+x4=...=x19+x20=x20+x21=1.tinh x 21
trả lời nhanh nhé,mình đang cần gấp
a) (x – 2)(x2 + 2x + 4) – x( x2 +2) = 12 b) (x – 3)2 – (x+2)(x–2) = 16
c) x3 – 9x = 0 d) x3 – 6x2 + 9x – 54 = 0
giúp e vs ạ
\(a,\Leftrightarrow x^3-8-x^3-2x=12\Leftrightarrow-2x=20\Leftrightarrow x=-10\\ b,\Leftrightarrow x^2-6x+9-x^2+4=16\Leftrightarrow=-6x=3\Leftrightarrow x=-\dfrac{1}{2}\\ c,\Leftrightarrow x\left(x^2-9\right)=0\\ \Leftrightarrow x\left(x-3\right)\left(x+3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\\x=-3\end{matrix}\right.\\ d,\Leftrightarrow x^2\left(x-6\right)+9\left(x-6\right)=0\\ \Leftrightarrow\left(x^2+9\right)\left(x-6\right)=0\\ \Leftrightarrow x=6\left(x^2+9>0\right)\)
Tìm x:
a) 36x3-4x=0
b) 3x(x-2)-2+x=0
c) (x3-x2)-4x2+8x-4=0
d) x2-6x-16=0
e) x4-6x2-7=0
(Mình cần gấp ạ)
a) Ta có: \(36x^3-4x=0\)
\(\Leftrightarrow4x\left(9x^2-1\right)=0\)
\(\Leftrightarrow x\left(3x-1\right)\left(3x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{3}\\x=\dfrac{-1}{3}\end{matrix}\right.\)
b) Ta có: \(3x\left(x-2\right)+x-2=0\)
\(\Leftrightarrow\left(x-2\right)\left(3x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{-1}{3}\end{matrix}\right.\)
d) Ta có: \(x^2-6x-16=0\)
\(\Leftrightarrow\left(x-8\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=8\\x=-2\end{matrix}\right.\)
e) Ta có: \(x^4-6x^2-7=0\)
\(\Leftrightarrow\left(x^2-7\right)\left(x^2+1\right)=0\)
\(\Leftrightarrow x\in\left\{\sqrt{7};-\sqrt{7}\right\}\)
tính bằng cách hợp lí
3,2 + 4,65 : 1,5
347 + 418 + 123 + 12
34 x 35 + 35 x 38 + 65 x 40 + 65 x 32
19 x 16 x 4 + 76 x 34
136 x 68 + 16 x2 x 136
125 x 25 + 125 x 74 + 125
AI BIẾT THÌ GIÚP MIK NHÉ! THANK
3,2 + 4,65 : 1,5
=3,2+3,1
=6,3
347 + 418 + 123 + 12
=(347+123)+(418+12)
=470+430
=900
34 x 35 + 35 x 38 + 65 x 40 + 65 x 32
=35*(34+38)+65*(32+40)
=35*72+65*72
=72*(35+65)
=72*100
=7200
19 x 16 x 4 + 76 x 34
=76*16+76*34
=76*(16+34)
=76*50
=3800
136 x 68 + 16 x2 x 136
=136*68+32*136
=136*(68+32)
=136*100
=13600
125 x 25 + 125 x 74 + 125
=125*(25+74+1)
=125*100
=12500
3,2 + 4,65 : 1,5 = 3,2 + 3,1 = 6,3
347 + 418 + 123 + 12 = (347 + 123) + (418 + 12) = 470 + 430 = 900
34 x 35 + 35 x 38 + 65 x 40 + 65 x 32 = 35 x ( 34 + 38) + 65 x (40 + 32) = 35 x 72 + 65 x 72 = 72 x (35 + 65) = 72 x 100 = 7200
19 x 16 x 4 + 76 x 34
136 x 68 + 16 x2 x 136
125 x 25 + 125 x 74 + 125
(3. 4x - 3).(x3 - 125) = 0
Giúp mình với ạ! ☺
\(\left(3.4^x-3\right).\left(x^3-125\right)=0\\ \rightarrow\left[{}\begin{matrix}3.4^x-3=0\\x^3-125=0\end{matrix}\right.\\ \rightarrow\left[{}\begin{matrix}3.4^x=3\\x^3=125\end{matrix}\right.\)
\(\rightarrow\left[{}\begin{matrix}4^x=1=4^0\\x^3=5^3\end{matrix}\right.\\ \rightarrow\left[{}\begin{matrix}x=0\\x=5\end{matrix}\right.\)
\(\left(3\cdot4^x-3\right)\left(x^3-125\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}3\cdot4^x-3=0\\x^3-125=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}3\left(4^x-1\right)=0\\x^3-5^3=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}4^x=1\\x=5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=5\end{matrix}\right.\)