giai bat phuong trinh thuong x mu hai cong 1 chia 3 tru x lon hon hoac bang khong
Những câu hỏi liên quan
Cho f(x)= x^2- 2(m+2)x + 2m^2 +10m +12=0. Tim m de bat phuong trinh f(x) Lon hon hoac bang 0 co tap nghiem R
Đã là BPT thì đề không được ghi f(x)=0 nha bạn mâu thuẫn quá!
f(x)=x2-2(m+2)x+2m2+10m+12(1)
Để f(x) lớn hơn 0 với mọi x thuộc R thì
\(\left\{{}\begin{matrix}\Delta'\ge0\\a>0\\\end{matrix}\right.\)
<=>\(\left\{{}\begin{matrix}\left(m+2\right)^2-2m^2-10m-12\ge0\\1>0\left(lđ\right)\end{matrix}\right.\)
<=>-m2-6m-8\(\ge\)0
<=>-(m+2)(m+4)\(\ge\)0
cho (m+2)(m+4)=0 <=> m=-2 hoặc m=-4
Bảng xét dấu:
Vậy m=[-4;-2]
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Giai bat phuong trinh sau: căn x^2-3x+10<hoac bang x-2
cho hàm số y=f(x)= 1/2 * x - 3 neu x lon hon hoac bang 6 va bang 3-1/2 * x neu x<6 ham so tren co the viet gon boi cong yhuc nao khong
viet tong sau thanh binh phuong cua mot so tu nhien , n lon hon hoac bang 1
1 mu 8 + 2 mu 8 + 3 mu 8 ......... n mu 8
bai 1 tim hai so khi biet hieu cua chung bang 8.7 va biet khi nhan so be voi 4 nhan so lon voi 3 thi duoc hai tich bang nhau
bai 2 trung binh cong cua hai so bang 189.6 tim so lon biet so lon hon so be 24.5 don vi
bai 3 tim 2 so biiet thuong cua chung bang 0.6 hieu cua chung bang 7.2
ai giai giup voi toi voi viet dap an ra nhe hoac guib ca bai giai nhe thi toi tick 100 cai luong luc nao gap toi cung tick chi can giain cho toi thoi nhe cam on cac ban
so tu nhien x thoa man dieu kien 0.(x-3)=0.so x bang
(A)0
(B)3
(C)so tu nhien bat ki
(D) so tu nhien bat ki lon hon hoac bang 3
Giai he phuong trinh bang phuong phap cong va phuong phap the
<=> \(\left\{{}\begin{matrix}4x+3x=-6\\\dfrac{x+3y}{3}-\dfrac{y-2}{5}=1\end{matrix}\right.\)
\(\left\{{}\begin{matrix}4x+3x=-6\\\dfrac{x+3y}{3}-\dfrac{y-2}{5}=1\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}7x=-6\\\dfrac{5\left(x+3y\right)-3\left(y-2\right)}{15}=1\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=-\dfrac{6}{7}\\5x+15y-3y+6=15\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=-\dfrac{6}{7}\\12y=9-5x=9+5\cdot\dfrac{6}{7}=9+\dfrac{30}{7}=\dfrac{93}{7}\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=-\dfrac{6}{7}\\y=\dfrac{93}{7\cdot12}=\dfrac{93}{84}=\dfrac{31}{28}\end{matrix}\right.\)
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5 mu n nhan 5 mu n cong 1 nhan 5 mu n cong 2 be hon hoac bang 10 mu 18
giai cac phuong trinh va bat phuong trinh sau:
2(x-1)-5=3(5-3x)
2( x - 1 ) - 5 = 3( 5 - 3x)
2x - 2 - 5 = 15 - 9x
2x - 7 = 15 - 9x
2x + 9x = 15 + 7
11x = 22
x = 2
Vậy x = 2
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\(2\left(x-1\right)-5=3\left(5-3x\right)\)
\(\Leftrightarrow2x-2-5=15-9x\)
\(\Leftrightarrow2x-\left(2+5\right)=15-9x\)
\(\Leftrightarrow2x-7=15-9x\)
\(\Leftrightarrow2x+9x=15+7\)
\(\Leftrightarrow11x=22\)
\(\Leftrightarrow x=22\div11\)
\(\Leftrightarrow x=2\)
\(\text{Vậy }x=2\)
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2( x - 1 ) - 5 = 3( 5 - 3x)
2x - 2 - 5 = 15 - 9x
2x - 7 = 15 - 9x
2x + 9x = 15 + 7
11x = 22
x = 2
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