Bài2:Tìm x biết
a.1/3+2/3:x=-7
b.1/3x+2/5(x-1)=0
c.(2x-3)(6-2x)=0
d.x:3/4+1/4=-2/3
e.-2/3-1/3(2x-5)=3/2
f.2 l1/2x-1/3l-3/2=1/4
g.3/4-2.l2x-2/3l=2
h.(-0,6x-1/2).3/4-(-1)=1/3
i.(3x-1)(-1/2x+5)=0
j.1/4+1/3:(2x-1)=-5
k.(2x+3/5)2-9/25=0
l.3(3x-1/2)3+1/9=0
m.-5(x+1/5)-1/2(x-2/3)=3/2x-5/6
n.3(x-1/2)-5(x+3/5)=-x+1/5
1. | 4-2x | . 1/3 = 1/3
2. (-3)² : | x+(-1) | = (-3)
3. | 3/2 -x | + (-4/5) = -14/5
4. (-4/3) - | 2x + (-1) | = -7/3
5. -9 . | 36 - x/2 | = (-54)
6. 0,75 - | (-x) + 1/3 | = 0,25
7. (-6/5) + | x-9 |= (-6/5)
8. (-4) . | 3x - 1/5 | = 12
m.-5(x+1/5)-1/2(x-2/3)=3/2x-5/6
n.3(x-1/2)-5(x+3/5)=-x+1/5
Tìm X:
a) 1/3 X + 2/5 (X - 1)=0
b) 1/2|X|+1/2=5/2
c) -2/3-1/3(2X-5)=3/2
d) (3X-1)(1/2X+5)=0
đ) 3 và 1/3+5/6X=3 và 1/2
Hãy điền các dấu +,-,x,:,( ), ngoặc vuông, ngoặc nhọn,... để kết quả là -1
1...2...3...4=-1
1...2...3...4...5=-1
1...2...3...4...5...6=-1
1...2...3...4...5...6...7=-1
1...2...3...4...5...6...7...8=-1
1...2...3...4...5...6...7...8...9=-1
1...2...3...4...5...6...7...8...9...10=-1
Tính hợp lí.a,A=-2/9+-3/4+3/5+1/15+1/57+1/3+-1/36 b, B=1/2+-1/5+-5/7+1/6+-3/35+1/3+1/41
Chứng Minh Rằng A=\(\dfrac{1}{1+3}+\dfrac{1}{1+3+5}+\dfrac{1}{1+3+5+7}+...+\dfrac{1}{1+3+5+...+2017}\)\(< \dfrac{3}{4}\)
3/5- -1/2 -5/7-1/3 -2/5- -3/4 -5-1/6
SGK ?4 (33)
Thực hiện phép tính:
a) 1/3 + -13/21 + 5/7 + 1/6 + 1/14 + -1/2
b) 1/3 + -1/4 + 1/5 + -1/6 + 1/7 + 1/6 + 1/-5 + 1/4 + 1/-3