1) x – 2 = -6
2) -5x – ( -3) = 13
3) 15- ( x -7 ) = – 21
4) 3x + 17 = 2
5) 45 – ( x- 9) = – 35
6) -7x – ( -9) = 30
7) x + (-3) = -11
8) -8x – (-11) = 43
9) 82 – (15 + x) = 72
10) (-5) + x = 15
11) 2x – (–17) = 15
12) |x – 2| = 3.
13) | x – 3| -7 = 13
14) 72 – 3.|x + 1| = 9
15) 17 – (43 – ) = 45
16) | x +9| – 7 = 12
17) 3| x – 1| – 5 = 7
18) 2x + 11 = 3(x – 9)
19) -15(x – 2) + 7(3 – x) = 7
20) -12(x – 5) + 7(3 – x) = 5
Tìm x ạ giúp e vs
Đáp án:
Giải thích các bước giải:
1.
x – 2 = -6
x= (-6) + 2
x= (-4)
2,
-5x – ( -3) = 13
-5x = 13 + (-3)
-5x= 10
x= 10 ÷ (-5)
x= -2
3,
15- ( x -7 ) = – 21
( x -7) = (-21) – 15
x -7 = -36
x= (-36) + (-7)
x= -43
4,
3x + 17 = 2
3x = 2 – 17
3x = – 15
x= (-15) ÷ 3
x= -5
5,
45 – ( x- 9) = – 35
( x – 9 )= 45 – (-35)
x-9 = 80
x= 80 + 9
x = 89
6,
-7x – ( -9) = 30
-7x = 30 + (-9)
-7x = 21
x = 21 ÷ (-7)
x = -3
7,
x + (-3) = -11
x = (-11) – (-3)
x = -8
8,
-8x – (-11) = 43
-8x = 43 + (-11)
-8x= 32
x = 32 ÷ (-8)
x = -4
9,
82 – (15 + x) = 72
( 15 + x) = 82 – 72
( 15 + x) = 10
x = 10 – 15
x= -5
10,
(-5) + x = 15
x = 15 – (-5)
x = 20
11,
2x – (–17) = 15
2x = 15 + (-17)
2x = -2
x = (-2) ÷ 2
x= -1
12,
|x – 2| = 3
x – 2 = 3 hoặc x-2=-3
x = 3 + 2 hoặc x=-3+2
x = 5 hoặc x=-1
13,
| x – 3| -7 = 13
|x – 3| = 13+7
x – 3 = 20 hoặc x-3=-20
x = 20+3 hoặc x=-20+3
x = 23 hoặc x=-17
14,
72 – 3.|x + 1| = 9
3|x +1| = 72-9
3|x + 1|= 63
|x + 1| = 63 : 3
|x + 1| = 21
x+1=21 hoặc x+1 = -21
x=21-1 hoặc x=-21-1
x=20 hoặc x=-22
15,
17 – (43 – x ) = 45
( 43 – x ) = 17-45
43 – x = -28
x = 43 – (-28)
x=71
16,
| x +9| – 7 = 12
|x + 9 | = 12+7
x+9 = 19 hoặc x+9=-19
x=19-9 hoặc x=-19-9
x=10 hoặc x=-28
17,
3| x – 1| – 5 = 7
3|x – 1| =7+5
3|x – 1| = 12
|x -1 |= 12:3
|x -1 |=4
x -1=4 hoặc x-1=-4
x=4+1 hoặc x=-4+1
x=5 hoặc x=-3
18,
2x + 11 = 3(x – 9)
2x + 11 = 3x – 27
3x – 2x = 11 + 27
x = 38
19,
-15(x – 2) + 7(3 – x) = 7
-15x-30 + 21-7x =7
-15x-7x=7+30-21
-22x=16
x=16:(-22)
x=$\frac{-16}{22}$
20
-12(x – 5) + 7(3 – x) = 5
-12x + 60 + 21 – 7x = 5
-12x-7x=5-60-21
-19x=-76
x=4
Giải
1.
x – 2 = -6
x= (-6) + 2
x= (-4)
2,
-5x – ( -3) = 13
-5x = 13 + (-3)
-5x= 10
x= 10 ÷ (-5)
x= (-2)
3,
15- ( x -7 ) = – 21
( x -7) = (-21) – 15
(x -7 )= ( -36)
x= (-36) + (-7)
x= (-43)
4,
3x + 17 = 2
3x = 2 – 17
3x = – 15
x= (-15) ÷ 3
x= -5
5,
45 – ( x- 9) = – 35
( x – 9 )= 45 – (-35)
(x-9) = 80
x= 80 + 9
x = 89
6,
-7x – ( -9) = 30
-7x = 30 + (-9)
-7x = 21
x = 21 ÷ (-7)
x = -3
7,
x + (-3) = -11
x = (-11) – (-3)
x = 14
8,
-8x – (-11) = 43
-8x = 43 + (-11)
-8x= 32
x = 32 ÷ (-8)
x = -4
9,
82 – (15 + x) = 72
( 15 + x) = 82 – 72
( 15 + x) = 10
x = 10 – 15
x= -5
10,
(-5) + x = 15
x = 15 – (-5)
x = 20
11,
2x – (–17) = 15
2x = 15 + (-17)
2x = -2
x = (-2) ÷ 2
x= -1
12,
|x – 2| = 3.
x – 2 = 3
x = 3 + 2
x = 5
13,
| x – 3| -7 = 13
x – 3 – 7 = 13
x – 3 = 13 -7
x – 3= 6
x = 6+ 3
x = 9
14,
72 – 3.|x + 1| = 9
72 – 3x +1 = 9
3x + 1 = 72 – 9
3x + 1 = 63
3x = 63 – 1
3x = 62
x= 62 ÷ 3
x= 20,6
15,
17 – (43 – x ) = 45
( 43 – x ) = 45 + 17
(43 – x ) = 62
x = 43 – 62
x = -19
16,
| x +9| – 7 = 12
x + 9 – 7 = 12
x+9 = 12 – 7
x + 9 = 5
x = 5+ 9
x = 14
17,
3| x – 1| – 5 = 7
3x – 1 -5 = 7
3x – 1 = 7 – 5
3x -1 = 2
3x = 7 – 1
3x = 6
x= 6 ÷ 3
x = 2
18,
2x + 11 = 3(x – 9)
2x + 11 = 3x – 27
3x – 2x = 11 + 27
x = 38
19,
Ko bít ;-;;;
20,
ko bít ;-;;
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