Ta có:
9 - (2/3 - x) = -5/4
2/3 - x = 9 - (-5/4)
2/3 - x = 9 + 5/4
2/3 + x = 41/4
x = 41/4 - 2/3
x = 123/12 - 8/12
x = 115/12
Ta có:
9 - (2/3 - x) = -5/4
2/3 - x = 9 - (-5/4)
2/3 - x = 9 + 5/4
2/3 + x = 41/4
x = 41/4 - 2/3
x = 123/12 - 8/12
x = 115/12
BT1: Tìm x, biết:
1) \(\left[\left(\dfrac{1}{2}x-\dfrac{1}{3}\right)^2+\dfrac{1}{4}\right]^3=\dfrac{1}{8}\)
BT1: Tìm x, biết:
6) \(\dfrac{1}{2}.\left(\dfrac{1}{3}x-\dfrac{1}{5}\right)^2-\dfrac{1}{5}=-\dfrac{3}{40}\)
BT1: Tìm x, biết:
5) \(\dfrac{1}{2}+\dfrac{1}{3}< x\le1\dfrac{1}{2}+\dfrac{1}{5}\left(x\in Z\right)\)
BT1: Tìm x, biết:
1) \(x+\dfrac{1}{4}=\dfrac{3}{5}-\left(-\dfrac{1}{3}\right)\)
BT1: Tính nhanh
2) \(\left(7-\dfrac{4}{3}+\dfrac{1}{3}\right)-\left(6+\dfrac{5}{4}-\dfrac{4}{3}\right)-\left(5-\dfrac{7}{4}+\dfrac{5}{3}\right)\)
1.Tính:
\(\left(\dfrac{-2}{3}\right)\)\(\times0.75+1\dfrac{2}{3}\div\left(\dfrac{-4}{9}\right)+\left(\dfrac{-1}{2}\right)^2\)
2.Tìm x:
a)\(\dfrac{3}{4}-\left(x+\dfrac{1}{2}\right)=\dfrac{4}{5}\)
b) \(\left|x-\dfrac{2}{5}\right|+\dfrac{3}{4}=\dfrac{11}{4}\)
3.Tìm n, biết:
a) \(\dfrac{16}{2^n}=2\)
b)\(\dfrac{\left(-3\right)^n}{81}=-27\)
4. Tìm ba số x,y,z biết:
\(\dfrac{x}{2}=\dfrac{y}{3};\dfrac{y}{5}=\dfrac{z}{4}\)và x-y+z= -49
BT1: Tính nhanh:
1) \(\dfrac{1}{2}-\left(\dfrac{-16}{17}\right)+\dfrac{4}{5}-\left(\dfrac{-4}{9}\right)-\dfrac{11}{45}+\dfrac{19}{34}+\dfrac{19}{105}\)
BT1: Tìm x, biết:
2) \(0,28-0,3:\left(50\%.x-1\dfrac{1}{3}\right)=-1\dfrac{2}{3}\)
1. tìm x
a, 2x - \(\dfrac{1}{2}\) : \(\dfrac{3}{4}\) = \(\dfrac{12}{9}\)
b, x\(^2\) - 2 = 0
2. Cho
A = \(\dfrac{1,11+0,19-13.2}{2,06+0,54}\) - \(\left(\dfrac{1}{2}+\dfrac{1}{4}\right)\) : 2
B = \(\left(5\dfrac{7}{8}-2\dfrac{1}{4}-0,5\right)\) : \(2\dfrac{23}{26}\)
a, Rút gọn A, B
b, Tìm x ϵ Z để A < x < B