Đáp án: a)x=31 b)x=-5 c)x=14 Giải thích các bước giải: a)128-3(x+4)=23 3(x+4)=128-23 3(x+4)=105 (x+4)=105:3 x+4=35 x=35-4 x=31 b)(4x+28).3+55:5=35 (4x+28).3+11=35 (4x+28).3=35-11 (4x+28).3=24 (4x+28)=24:3 4x+28=8 4x=8-28 4x=-20 x=-20:4 x=-5 c)720:41-(2x-5)=2^3.5 720:41-(2x-5)=8.5 720:41-(2x-5)=40 41-(2x-5)=720:40 41-(2x-5)=18 (2x-5)=41-18 2x-5=23 2x=23+5 2x=28 x=14 Reply
a) 128 – 3(x+4) = 23 3(x+4) = 128 – 23 3(x+4) = 105 x + 4 = 105 : 3 x + 4 = 35 x = 35 – 4 x = 31 b) [(4x+28).3+55]: 5=35 (4x+28).3+55 =35.5 (4x+28).3+55 = 175 (4x+28).3 = 175 – 55 (4x+28).3 = 120 4x + 28 = 120 : 3 4x + 28 = 40 4x = 40 – 28 4x = 12 x = 12 : 4 x = 3 c) 720 : [41-(2x-5)]=23.5 720 : [41-(2x-5)] = 8.5 720 : [41-(2x-5)] = 40 [41-(2x-5)] = 720:40 [41-(2x-5)] = 18 (2x-5) = 41 – 18 2x-5 = 23 2x = 23 + 5 2x = 28 x = 28 : 2 x =14 CHÚC BẠN HỌC TỐT! BY@CUGIAI2K9 NOCOPY# Reply
Đáp án:
a)x=31 b)x=-5 c)x=14
Giải thích các bước giải:
a)128-3(x+4)=23
3(x+4)=128-23
3(x+4)=105
(x+4)=105:3
x+4=35
x=35-4
x=31
b)(4x+28).3+55:5=35
(4x+28).3+11=35
(4x+28).3=35-11
(4x+28).3=24
(4x+28)=24:3
4x+28=8
4x=8-28
4x=-20
x=-20:4
x=-5
c)720:41-(2x-5)=2^3.5
720:41-(2x-5)=8.5
720:41-(2x-5)=40
41-(2x-5)=720:40
41-(2x-5)=18
(2x-5)=41-18
2x-5=23
2x=23+5
2x=28
x=14
a) 128 – 3(x+4) = 23
3(x+4) = 128 – 23
3(x+4) = 105
x + 4 = 105 : 3
x + 4 = 35
x = 35 – 4
x = 31
b) [(4x+28).3+55]: 5=35
(4x+28).3+55 =35.5
(4x+28).3+55 = 175
(4x+28).3 = 175 – 55
(4x+28).3 = 120
4x + 28 = 120 : 3
4x + 28 = 40
4x = 40 – 28
4x = 12
x = 12 : 4
x = 3
c) 720 : [41-(2x-5)]=23.5
720 : [41-(2x-5)] = 8.5
720 : [41-(2x-5)] = 40
[41-(2x-5)] = 720:40
[41-(2x-5)] = 18
(2x-5) = 41 – 18
2x-5 = 23
2x = 23 + 5
2x = 28
x = 28 : 2
x =14
CHÚC BẠN HỌC TỐT!
BY@CUGIAI2K9
NOCOPY#