219 - 7 x (x + 1)=100
(3x - 6) x 3=3^4
tìm x :
a) 219 - 7 ( x + 1 ) = 100
b) (3x - 6 ) . 3 = 34
a) 219 – 7(x + 1) =100
7(x+1) = 219 -100
7(x+1) = 119
x + 1 = 119:7
x + 1 = 17
x = 17-1
x = 16
b) (3x – 6).3 = 34
3x – 6 = 34 : 3
3x – 6 = 33
3x = 27 + 6
3x = 33
x = 11
a ) 219 - 7( x + 1 ) = 100
7 ( x + 1 ) = 219 - 100
7 ( x + 1 ) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
b ) ( 3x - 6 ) . 3 = 34
( 3 x - 6 ) . 3 = 81
3x - 6 = 81 : 3
3x - 6 = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
Tìm số tự nhiên x, biết a) 219 – 7(x + 1) =100; b) (3x – 6).3 = 3/4
a)
<=> 219 - 7x - 7 = 100
<=> -7x = 100 - 219 + 7
<=> -7x = -112
<=> x = -112 : (-7)
<=> x = 16
b)
<=> 9x - 18 = 34
<=> 9x = 34 + 18
<=> 9x = 52
<=> x = 52 : 9
<=> x = 52/9
a)219-7(x+1)=100
7(x+1)=219-100
7(x+1)=119
x+1 =119:7
x+1 =17
x =17-1
x =16
b) (3x-6).3=34
3x-6 =34:3
3x-6 =\(\frac{34}{3}\)
3x =\(\frac{34}{3}\)- 6
3x =\(\frac{16}{3}\)
x =\(\frac{16}{3}\): 3
x =\(\frac{16}{9}\)
a. 219 - 7(x + 1) = 100 b. ( 3x - 6).3 = 36 c. 716 - (x - 143) = 659
d. 30 - [4(x - 2) + 15] = 3 e. [(8x - 12) : 4].33 = 36
a.219 - 7(x+1) = 100
7(x+1) = 219 - 100
7(x+1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
b. (3x - 6 ) . 3 = 36
3x - 6 = 36 : 3
3x - 6 = 12
3x = 12 + 6
3x = 18
x = 18 : 3
x = 6
c.716 - ( x-143) = 659
x-143 = 716 - 659
x-143 = 57
x = 57 + 143
x = 200
b. 30 - [4(x-2)+15] = 3
4(x-2) + 15 = 30 - 3
4(x-2)+15 = 27
4(x-2) = 27 - 15
4(x-2) = 12
x-2 = 12 : 4
x-2 = 3
x = 2 + 3 = 5
e.[(8x - 12) : 4] .33 = 36
[(8x - 12) : 4] . 27 = 729
(8x - 12) : 4 = 729 : 27 = 27
8x - 12 = 27 . 4 = 108
8x = 108 + 12 = 120
x = 120 : 8 = 15
a) \(\Leftrightarrow7\left(x+1\right)=119\\ \Leftrightarrow x+1=17\\ \Leftrightarrow x=16\)
b) \(\Leftrightarrow9\left(x-2\right)=36\\ \Leftrightarrow x-2=4\\ \Leftrightarrow x=6\)
c) \(\Leftrightarrow x-143=57\\ \Leftrightarrow x=200\)
d) \(\Leftrightarrow4\left(x-2\right)+15=27\\ \Leftrightarrow4\left(x-2\right)=12\\ \Leftrightarrow x-2=3\\ \Leftrightarrow x=5\)
e) \(\Leftrightarrow\left(2x-3\right).4:4=3^3\\ \Leftrightarrow2x-3=27\\ \Leftrightarrow2x=24\\ \Leftrightarrow x=12\)
a. 219 - 7(x + 1) = 100 b. ( 3x - 6).3 = 36 c. 716 - (x - 143) = 659
7(x+1)=119 3x-6=12 716-x+143=659
x+1=17 3x=18 859-x=659
x=16 x=6 x=200
d. 30 - [4(x - 2) + 15] = 3 e. [(8x - 12) : 4].33 = 36
4(x-2)+15=27 (8x-12):4=27
4(x-2)=12 8x-12=6,75
x-2=3 8x=18,75
x=5 x=\(\dfrac{75}{32}\)
bài 13: tìm x biết
a. 124 + (118 - x) = 217
b. 156- (x + 61) = 82
c. 219 - 7(x + 1) = 100
d. (3x - 6). 3 = 3^4
e. 231 - (x - 6) = 1339 : 13
a) 124 + (118 - x) = 217
118 - x = 217 - 124
118 - x = 93
x = 118 - 93
x = 25
b) 156 - (x + 61) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
c) 219 - 7(x + 1) = 100
7(x + 1) = 219 - 100
7(x + 1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
d) (3x - 6).3 = 3⁴
3x - 6 = 3⁴ : 3
3x - 6 = 3³
3x - 6 = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
e) 231 - (x - 6) = 1339 : 13
231 - (x - 6) = 103
x - 6 = 231 - 103
x - 6 = 128
x = 128 + 6
x = 134
a) 124 + (118 - x) = 217
118 - x = 217 - 124
118 - x = 93
x = 118 - 93
x = 25
b) 156 - (x + 61) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
c) 219 - 7(x + 1) = 100
7(x + 1) = 219 - 100
7(x + 1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
d) (3x - 6) . 3 = 34
(3x - 6) . 3 = 81
(3x - 6) = 81 : 3
(3x - 6) = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
e) 231 - (x - 6) = 1339 : 13
231 - (x - 6) = 103
(x - 6) = 231 - 103
x - 6 = 128
x = 128 + 6
x = 134
cô cấm dùng máy tính -)
lớp 9 ms đc dùng:_)
giúp mình 2 bài tìm x này với:
a) 219 - 7 (x + 1) = 100
b) (3x - 6) x 3 = 3^4
a/ => 7(x + 1) = 119
=> x + 1 = 17
=> x = 16
b/ => 3x - 6 = 33 = 27
=> 3x = 33
=> x = 11
tùim số tự nhiên x ,
219 - 7 (x+1) = 100 (3x - 6).3 = 34
219 - 7(x+1)=100 (3x-6).3=34
=> 7(x+1)=219-100 => 3x-6=34:3
=> 7(x+1)=119 => 3x-6=32=9
=> x+1=119:7 => 3x=9+6
=> x+1=17 => 3x=15
=> x=17-1 => x=15:3
=> x=16 => x=5
Vậy x=16 Vậy x=5
tìm số tự nhiên x, biết:
a) 219-7(x+1)= 100 b) (3x-6) . 3= 3 mũ 4
a)219-7(x+1)=100
7(x+1)=219-100
7(x+1)=119
x+1=119:7
x+1=17
x=17-1
x=16
b)(3x-6).3=34
(3x-6).3=81
3x-6=81:3
3x-6=17
3x=27+6
3x=33
x=33:3
x=11
li-ke cho mình nha Duong Thi Hoai My
nếu gì nguyện cau chúc củat bai t0an va thay s0 thi sa0
Tìm số tự nhiên x, biêt:
a, 219 - 7(x + 1) = 100
b, (3x - 6) . 3 = 34
a)
\(219-7\left(x+1\right)=100\)
\(\Rightarrow7\left(x+1\right)=119\)
\(\Rightarrow x+1=17\)
=> x = 16
Vậy x = 16
b)
\(\left(3x-6\right)3=3^4\)
\(\Rightarrow\left(x-2\right)3^2=3^4\)
=> x - 2 = 9
=> x = 7
Vậy x = 7
Giải:
a, 219 - 7(x + 1) = 100
7(x + 1) = 219 - 100
7(x + 1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
b, (3x - 6) . 3 = 34
(3x - 6) . 3 = 81
3x - 6 = 81 : 3
3x - 6 = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
Tìm số tự nhiên x, biết:
a. 219 - 7(x+1) = 100
b. (3x - 6) . 3 = 34
a. 219 - 7(x+1) = 100
7(x+1)=119
x+1=119:7
x+1=17
x=16
Vậy x=16
b. (3x - 6) . 3 = 34
3x-6=34:3
3x-6=33
3x=33
x=11
Vậy x=11
a) \(219-7\left(x+1\right)=100\)
\(\Leftrightarrow219-7x-7=100\)
\(\Leftrightarrow-7x=100-219+7=-112\)
\(\Leftrightarrow x=16\)
b) \(\left(3x-6\right)\cdot3=3^4\)
\(\Leftrightarrow\left(x-2\right)\cdot3^2=3^4\)
\(\Leftrightarrow x-2=3^2\)
\(\Leftrightarrow x=9+2=11\)
a) \(219-7\left(x+1\right)=100\)
\(\Rightarrow7\left(x+1\right)=119\)
\(\Rightarrow x+1=119:7\)
\(\Rightarrow x+1=17\)
\(\Rightarrow x=16\)
b) \(\left(3x-6\right)3=3^4\)
\(\Rightarrow\left(3x-6\right)=3^3:3\)
\(\Rightarrow\left(3x-6\right)=3^3\)
\(\Rightarrow\left(3x-6\right)=27\)
\(\Rightarrow3x=27-6\)
\(\Rightarrow3x=21\)
\(x=21:3\)
\(\Rightarrow x=7\)