Giúp em với ạ !!
Tìm x thuộc Z: (x-1)x+2=(x-1)x+6.
1)Tính hợp lý:
a: (36-16).(-5)+6.(-14-6)
2)Tìm x thuộc Z
a/ x+(-23)=(-100)+77
b/ x-(5-x)=x-15
GIÚP MÌNH VỚI MÌNH CẦN GẤP Ạ, MÌNH CẢM ƠN NHIỀU
2. a) x + (-23) = (-100) + 77
1)
a: (36-16).(-5)+6.(-14-6)
=20.(-5)+6.(-20)
=20.(-5)+(-6).20
=20.(-5+-6)
=20.(-11)
=-220
2)
a/x+(-23)=(-100)+77
x+(-23)=-23
x=(-23)+(-23)
x=0
Vậy x=0
Mọi người giúp em bài này với ạ!!!!
Tìm x thuộc Z biết |x-1|+|x-2|+...+|x-100|=2500tìm phần số x/9 (x thuộc z) sao cho:
x/9<4/7<x+1/9
GIÚP MÌNH VỚI Ạ. MÌNH CẦN GẤP. CẢM ƠN CÁC BẠN NHIỀU!
CÔ NGUYỄN THỊ THƯƠNG HOÀI GIÚP EM VỚI Ạ
\(\dfrac{x}{9}\) < \(\dfrac{4}{7}\) < \(x\) + \(\dfrac{1}{9}\)
\(\dfrac{7x}{63}\) < \(\dfrac{36}{63}\) < \(\dfrac{63x}{63}\) + \(\dfrac{7}{63}\)
7\(x\) < 36 < 63\(x\) + 7
⇒\(\left\{{}\begin{matrix}7x< 36\\63x+7>36\end{matrix}\right.\)⇒\(\left\{{}\begin{matrix}x< \dfrac{36}{7}\\63x>36-7\end{matrix}\right.\)⇒\(\left\{{}\begin{matrix}x< \dfrac{36}{7}\\63x>29\end{matrix}\right.\)⇒\(\left\{{}\begin{matrix}x< \dfrac{36}{7}\\x>\dfrac{29}{63}\end{matrix}\right.\)
\(\dfrac{29}{63}\)< \(x\) < \(\dfrac{36}{7}\) vì \(x\in\) Z nên \(x\in\) { 1; 2; 3; 4; 5}
⇒ \(\dfrac{x}{9}\) = \(\dfrac{1}{9}\); \(\dfrac{2}{9}\); \(\dfrac{3}{9}\); \(\dfrac{4}{9}\);\(\dfrac{5}{9}\)
tìm phần số x/9 (x thuộc z) sao cho:
x/9<4/7<x+1/9
GIÚP MÌNH VỚI Ạ. MÌNH CẦN GẤP. CẢM ƠN CÁC BẠN NHIỀU!
CÔ NGUYỄN THỊ THƯƠNG HOÀI GIÚP EM VỚI Ạ
\(\dfrac{x}{9}< \dfrac{4}{7}< \dfrac{x+1}{9}\)
=>\(\dfrac{7x}{63}< \dfrac{36}{63}< \dfrac{7x+7}{63}\)
\(\Rightarrow7x< 36< 7x+7\)
\(\Rightarrow x< \dfrac{36}{7}< x+1\)
\(\Rightarrow x< 5\dfrac{1}{7}< x+1\)
\(\Rightarrow x=5\)
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Tìm x thuộc Z, biết:
x + (x + 1) + (x + 2) + .... + (x + 2003) = 4 + 1007 * 2003
Mọi người giúp mình với ạ!
Ta có: \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+2003\right)=4+1007\cdot2003\)
\(\Leftrightarrow2004x+\dfrac{2003\cdot2004}{2}=4+1007\cdot2003\)
\(\Leftrightarrow2004x=10019\)
hay \(x=\dfrac{10019}{2004}\)
giúp e giải bài này với ạ !!!
a, tìm x thuộc Z để P thuộc Z ( P = -4x^2 chia x+2 ,,,, là phân số ạ )
b, tìm m để với mọi x >3 ta có m(x-3) P > x^2 + 1
Bài 1 : Tính :
A = 1 + 2 - 3 + 4 + 5 - 6 + ..... + 98 - 99
B = - 2 - 4 + 6 - 8 + 10 + 12 - ..... + 60
Bài 2 : Tìm x thuộc Z để :
a) | x | < 3
b) | x - 4 | < 3
c) | x + 10 | < 2
Bài 3 : Tìm a ; b thuộc Z để :
| a | + | b | = 1
Nhờ mọi người giúp mình với ạ ^_^ ai biết làm bài nào thì cmt dưới với ạ :))
Mong được có sự giúp đỡ của mọi người =)))
Bài 2:
a)|x| < 3
x\(\in\){-2;-1;0;1;2}
b)|x - 4 | < 3
x\(\in\){ 6 ; 5 ; 4 ; 3 ; 2 }
c) | x + 10 | < 2
x\(\in\){ -2 ; -10 }
Bài 1:
A = 1 + 2 - 3 + 4 + 5 - 6 +...+98 - 99
A = (1 + 4 + 7 +...+97) + [(2-3)+(5-6)+...+(98-99)]
A = 1617 + [(-1)+(-1)+...+(-1)]
A = 1617 + (-49)
A = +(1617-49) = A = 1568
B = - 2 - 4 + 6 - 8 + 10 + 12 - .... + 60
B =
2)
a) \(x\in\left\{2;1;0;-1;-2\right\}\)
b) \(x\in\left\{6;-6;5;-5;4\right\}\)
c) \(x\in\left\{-9;-11;-10\right\}\)
3)
\(\left(a;b\right)\in\left\{\left(0;1\right);\left(0;-1\right);\left(1;0\right);\left(-1;0\right)\right\}\)
Tìm tập hợp các số x thuộc Z biết
-5/6 + 8/3 + -29/3 ≤ x ≤ -1/2 + 2 + 5/2
Giúp em đi ạ
\(-\frac{5}{6}+\frac{8}{3}-\frac{29}{3}\le x\le-\frac{1}{2}+2+\frac{5}{2}\)
\(-7,8\left(3\right)\le x\le4\)
Mà \(x\in Z\)
\(\Rightarrow x\in\left\{-6;-5;-4;-3;-2;-1;0;1;2;3;4\right\}\)
Tìm x thuộc Z để P=x+3/căn x +1 thuộc Z
Moi người giúp mình với ạ!Thanks