a)
15/34 - 12/21 + 19/34 - 20/15 - 3/7
= (15/34 + 19/34) - (12/21 + 3/7) - 20/15
= 1 - 1 - 4/3
= -4/3
b)
(-1/3)^2 - |-4/3| + √49/9
= 1/9 - 4/3 + 7/3
= -2/9
c)
1/5 - (-7/8) - (-3/2) + (-7/8)
= 1/5 + 7/8 + 3/2 - 7/8
= 1/5 + 3/2
= 17/10
d)
8 - (2023/2024)^0 + (1/2)^2 * 5/4
= 8 - 1 + 1/4 * 5/4
= 7 + 5/16
= 117/16
Câu 14:
a)
3x - 4/3 = 1/2
3x = 1/2 + 4/3
3x = 11/6
x = 11/18
b)

(1 - 3x)^3 = -27
1 - 3x = -3
3x = 4
x = 4/3
c)
3/2 - |3 + 1/4x| = -0.5
|3 + 1/4x| = 3/2 + 0.5
|3 + 1/4x| = 2
Trường hợp 1: 3 + 1/4x = 2
1/4x = -1
x = -4
Trường hợp 2: 3 + 1/4x = -2
1/4x = -5
x = -20
d)
4^x = (16^2 * 4^5) / 64
4^x = (4^4 * 4^5) / 4^3
4^x = 4^(4+5-3)
4^x = 4^6
x = 6