a)58+7x=100
⇔7x=42
⇔x=6
b)4(x-51)=2.22+20
⇔4x-204=28
⇔4x=232
⇔x=58
c)2x-49=5.32
⇔2x-49=45
⇔2x=94
⇔x=47
a)58+7x=100
⇔7x=42
⇔x=6
b)4(x-51)=2.22+20
⇔4x-204=28
⇔4x=232
⇔x=58
c)2x-49=5.32
⇔2x-49=45
⇔2x=94
⇔x=47
x -56 : 4= 16
101 +(36 –4x) =105
2(x-51) = 2.23+ 20
10 -(x –3): 2 = 72–110
2x –49 = 5.32
[(8x -12) : 4].33= 36
52x –3–2 . 52= 52. 3
(x3–7) : 4 = 5
Tìm số tự nhiên x,biết:
a)58 + 7x = 100
b) ( x –12):12=12
c) x -56 : 4= 16
d) 101 +(36 –4x) =105
e) 2(x-51) = 2.23+ 20
f) 10 -(x –3): 2 = 72–110
g) 2x –49 = 5.32h) [(8x -12) : 4].33= 36
i) 52x –3–2 . 52= 52. 3 k) (x3–7) : 4 = 5
Tìm x biết:
a)58+7x=100
b)3x - 7=28
c)x - 56:4=16
d)101+(36-4x)=105
e) (x - 12 ) : 12 = 12
f) (3.x-24).73=2.74
i) (10+2x) .42011=42013
3. tìm số tự nhiên x biết
a 100 - 7x [ x - 5] = 58
b 24+5 nhân x = 49
c x- 105 : 21 = 15
d { x- 105] : 21 =15
Bài 1 :Tính một cách hợp lý
1) 39×51+39×49
2) 50×62+100×19
3) 49×53-51-49×53+69
4) 179-59×78-79+59
5) 35×(41-12)+41×(37-35)
Bài 2: thu gọn phép tính
a) 51-x +3x - 16
b) 75- 2x - 25 - x
c) x - 76 + 4x - 24
d) (2x - 17) - (51 - 6x)
e) (10a - 5) -(7a+15)
f) -20:2^2+(-5)^9:5^8
g)-100:5^2+-7.(-3)^2
h)-84:4+3^9:(-3)^7+(-5)^0
i)-29-[16+3.(51-49)]
j)-58.75+58.(-50)-58.(-25)
a/(-4) x(-3)x(-125)x25x(-8)
b/ (-4)x9x(-125)x25x(-8)
c/ 7x(-25)x(-3)x2x(-4)
d/ [93-(20-7)] : 16
e/ 53-(-51)+(-53)+49
f/ 168-49+(-68)+4
Bài 1:
a,-[x+84]+213=-16
b,11-[-53+x]=97
c,/x+10/=105-[-100]
d,/17-x/-78=99-176-[34-51]
e,/x-4/-x+4=0
g,6+/6-2x/-2x=0
h,/8x-9/=/6-7x/
i,/3x+15/-/5-2x/=0
1.
a) 2x + 5 = 34 : 32
b) ( 3x - 24 ) . 73 = 2.74
c) [ 3 . ( 42 - x ) + 15 = 23 . 3
d) 126 + ( 132 - x ) = 300
2.
a) 120 - ( x + 55 ) = 60
b) ( 7x - 11)3 = 25 .52 + 200
c) 2x + 2x+4 = 544
3.
a) 10 + 2x = 49 : 47
b) 70 - 5 ( x - 3 ) = 45
c) 4 + 95 : x = 143 : 142 - 23