20 : ( x - 5 ) = 4 . 25 - 20
20 : ( x - 5 ) = 80
x - 5 = 20 : 80
x - 5 = 0.25
x = 0,25 + 5
x = 5,25
( 4 + 3 ) ( x - 5 ) + 14 = = 25 + 124 : 4
7 ( x - 5 ) + 14 = 56
7 ( x - 5 ) = 56 - 14
7 ( x - 5 ) = 42
x - 5 = 42 : 7
x - 5 = 6
x = 6 + 5
x = 11
20 : ( x - 5 ) = 4 . 25 - 20
20 : ( x - 5 ) = 80
x - 5 = 20 : 80
x - 5 = 0.25
x = 0,25 + 5
x = 5,25
( 4 + 3 ) ( x - 5 ) + 14 = = 25 + 124 : 4
7 ( x - 5 ) + 14 = 56
7 ( x - 5 ) = 56 - 14
7 ( x - 5 ) = 42
x - 5 = 42 : 7
x - 5 = 6
x = 6 + 5
x = 11
1,Tính nhanh
a, 568 + 568 x 135 - 568 x 36
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
11×(x-9)+22=99
4×(x-3)+1=49
25+3×(x-8)=106
9×(x-4)-25=20
5+20÷(x+3)=7
25-14÷(2×X-3)=23
5+4×(2×X-3)=25
40-21÷(2×X+3)=33
14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
BÀI 1: Tính
1) -(-10)-(+14)
2) -(+15)-12
3) (-11)-(-13)
4) -(-13)-(-10)
5) -4-(+7)
BÀI 2: Tìm x biết:
1) x+(-5)= -(-7)
2) x-8= -(+10)
3) x-(-12)= 14
4) x-(+3)= -17
5) x+20= -(-23)
BÀI 3: Tính:
1) 17-(-19)-(+25)
2) -[-13]-[15]+(-20)
3) [-17]-(-16)-(+23)
4) -(-25)-[-14]+[-17]
bài 1 : Tìm x
a) 5 + ( x + 27 ) = 64
b) 64 - ( x - 2 ) = 25
c) 7 - ( x + 5 ) + 14 = 343
d) 5 . x - 25 = 10
e) 4 . ( x - 5 ) - 8 = 48
f) 49 - ( 15 + x ) = 12
g) 49 - 7. ( 13 - x ) = 14
h) 155 - 10. ( x + 1 ) = 55
13 x 58 x 4 + 32 x 26 x 2 + 52 x 10
15 x 37 x 4 + 120 x 21 + 21 x 5 x 12
14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
10 x ( 81 + 19 ) + 100 + 50 x ( 91 + 9 )
tính nhanh nha trình bày đầy đủ mk k 3 sao ( ^^ )
25-5*[4+x]=15
16-2*[15-x]=10
49-7*[13*x]=14
14*x-2*49=2*3*7
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
tìm x
3^x.(9^2)^3= 3^14
3^x+^3-3^2=234
(5^2+5^4+..........+5^20).(5^2-1)= 5^x-25