tìm x , biết:
a) \(x\) : \(4\dfrac{1}{3}\) = -2,5 b) \(\dfrac{3}{5}x\) + \(\dfrac{1}{4}\) = \(\dfrac{1}{10}\)
c) \(2\dfrac{7}{9}\) \(-\) \(\dfrac{12}{13}x\) = \(\dfrac{7}{9}\) d)\(\dfrac{-2}{3}-\dfrac{1}{3}\)\(\left(2x-5\right)=\dfrac{3}{2}\)
Bài 12: Tính :
a) A = 1 + (-3) + 5 + ( - 7) +….+ 17 + ( -19);
b) B = (- 2) + 4 + (-6) + 8 + …+ ( - 18) + 20;
c) C = 1 + (-2) + 3 + (-4) + ….+ 1999 + ( - 2000) + 2001;
Bài 13: Tìm số nguyên x, biết:
a) –x + 20 = -(-15) –(+8) + 13
b) –(-10) + x = -13 + (-9) + (-6)
Tìm x
a. (4\(x\)+5) :3 -121 :11=14
b. 2+4+6+..... +\(x\) =2450 (\(x\) chẵn)
c. 1\(x\)32 +7\(x\)8 +4\(x\)=200\(x\)
d.2\(x\)+3\(x\)=1505
Cần gấp ạ
1) Tính bằng cách hợp lí:
a) -4/7 + 3/7 + -4/5 + 4/7 - 2334
b) 5/13 + 4/19 + -8/13 + 15/19 + 456
2) Tìm x biết
a) 3/7 - x = -11/14
b) x - 4/9 = -12/9 + 3/18
GIÚP MÌNH VỚI, MIK CẦN GẤP LẮM
Tìm x biết:a) 10/x = -15/9; b) x/9 = -11/5 : 0,6; c) -7/8 - 2x = -3/4; d) (x-1/2):1/3+5/7=9và5/7; e)1/15.x+4/5.x=5và1/5; f) -1/3<x/6<1/2(x thuộc Z); h) 3/5+2/5:x=-1/4;i) 4 và 3/4x - 3 và 1/2=5/4; k)9/4.(1/3x-1/2)=4và1/2
Tìm x, biết:
a) \(\dfrac{3}{4}x\) - \(\dfrac{7}{12}\) = \(\dfrac{5}{6}\) - \(\dfrac{2}{3}\)
b) -\(\dfrac{5}{x}\) = \(\dfrac{20}{28}\)
c) \(2\dfrac{1}{3}\) : x = 7
d) \(\dfrac{-105}{12}\) < x < \(\dfrac{20}{7}\)
Tìm x, biết:
a) x+\(\dfrac{1}{6}\)=\(\dfrac{-3}{8}\) b) \(2-\left(\dfrac{3}{4}-x\right)=\dfrac{7}{12}\)
c) \(\dfrac{1}{2}x\)+\(\dfrac{1}{8}x=\dfrac{3}{4}\) d) 75%-\(1\dfrac{1}{2}+0,5:\dfrac{5}{12}-\left(\dfrac{-1}{2}\right)^2\)
Bài toán 3 : Tìm x, biết.
a. 2(x – 5) – 3(x + 7) = 14 b. 5(x – 6) – 2(x + 3) = 12
c. 3(x – 4) – (8 – x) = 12 d. -7(3x – 5) + 2(7x – 14) = 28
e. 5(3 – 2x) + 5(x – 4) = 6 – 4x f. -5(2 – x) + 4(x – 3) = 10x – 15
g. 2(4x – 8) – 7(3 + x) = |-4|(3 – 2) h. 8(x – |-7|) – 6(x – 2) = |-8|.6 – 50
k. -7(5 – x) – 2(x – 10) = 15 l. 4(x – 1) – 3(x – 2) = -|-5|
m. -4(x + 1) + 89x – 3) = 24 n. 5(x – 30 – 2(x + 6) = 9
o. -3(x – 5) + 6(x + 2) = 9 p. 7(x – 9) – 5(6 – x) = – 6 + 11x
q. 10(x – 7) – 8(x + 5) = 6.(-5) + 24
tìm x thuộc Z biết:
1) 2(4x-8)-7(3+x)=[-4](3-2)
2) 12(x-4)+6(x-2)-16(x+3)=7[-4]
3) 4(x-5)-7(5-x)+10(5-x)=-3
4) -3[x+5]=15(-3)+7(-3)
5) 4[x-7]-3(-5)=-2[x-7]-10
Tìm x, biết:
a) \(x:\dfrac{6}{13}=\dfrac{13}{7}\) b) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\) c) \(\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\) d) \(\dfrac{2}{3}.x-\dfrac{7}{6}=\dfrac{5}{2}\)