Đáp án:
Giải thích các bước giải:
(Mik ko ghi đề lại nha)
Bài 1:
a/ = 13/3 . 2/5 - 2/5 . 1/3 + 2/5
= 2/5.(13/3 - 1/3 + 1)
= 2/5.(12/3 + 1)
= 2/5.(4 + 1)
= 2/5. 5 = 2
b/ = 100/123. (9/12 + 7/12) + 23/123. (27/15 - 7/15)
= 100/123. 4/3 + 23/123. 4/3
= 4/3. (100/123 + 23/123)
= 4/3. 1 = 4/3
d/ = (3/5 - 7/9 + 7/5 - 2/9) : 83/4
= [(3/5 + 7/5) - (7/9 + 2/9)] : 83/4
= (2 - 1) : 83/4
= 1 : 83/4
= 1. 4/38 = 4/38
e/ = 12^4. 10^2 / 5^4 . 4^5 . 5^2
= (2^2 . 3)^4 . (2 . 5)^2 / 5^6 . (2^2)^5
= 2^8 . 3^4 . 2^2 . 5^2 / 5^6 . 2^10
= 3^4 / 5^4
= 81 / 625
Câu c mik ko bt lm :<<< Sorry bn :<<<
Bài 2:
d/ => |x - 5/3| - 1/4 = 3/4
=> |x - 5/3| = 3/4 + 1/4
=> |x - 5/3| = 1
=> x - 5/3 = 1
=> x = 1 + 5/3
=> x = 3/3 + 5/3
=> x = 8/3
e/ => 2^2x+1 = 2^5
=> 2x + 1 = 5
=> 2x = 5 - 1
=> 2x = 4
=> x = 4 : 2
=> x = 2
c/ => ( x - 1/2)^2 = (3/5)^2 = (-3/5)^2
TH1: x - 1/2 = 3/5
=> x = 3/5 + 1/2
=> x = 6/10 + 5/10
=> x = 11/10
TH2: x - 1/2 = -3/5
=> x = -3/5 + 1/2
=> x = -6/10 + 5/10
=> x = -1/10
a/ -1/4 + 1/4 : x = -5/8
=> 1/4 : x = -5/8 - (-1/4)
=> 1/4 : x = -5/8 + 2/8
=> 1/4 : x = -3/8
=> x = 1/4 : (-3/8)
=> x = 1/4. (-8/3)
=> x = -2/3
b/ => -4/9 + |3x + 1/2| = 2 - 4/9
=> -4/9 + |3x + 1/2| = 18/9 - 4/9
=> -4/9 + |3x + 1/2| = 14/9
=> |3x + 1/2| = 14/9 - (-4/9)
=> |3x + 1/2| = 14/9 + 4/9
=> |3x + 1/2| = 18/9
=> |3x + 1/2| = 2
=> 3x + 1/2 = 2
=> 3x = 2 - 1/2
=> 3x = 4/2 - 1/2
=> 3x = 3/2
=> x = 3/2 : 3
=> x = 3/2. 1/3
=> x = 1/2
