2 x ( x - 31 ) + 100 = 210
Tìm số nguyên x biết 210-(x+31)=-29
Tìm các số nguyên x sao cho -5/2<3/x <2/3
\(210-\left(x+31\right)=-29\)
\(\Rightarrow\left(x+31\right)=210-\left(-29\right)\)
\(\Rightarrow x+31=239\)
\(\Rightarrow x=239-31=208\)
\(-\frac{5}{2}< \frac{3}{x}< \frac{2}{3}\)
Các số nguyên x thỏa mãn là: x \(\in\left\{5;6;......\right\}\)
tính
x+(x+1)+(x+2)+...+(x+100)=210
x+(x+1)+(x+2)+...+(x+100) = 210
=> 101x + 100 x (100 + 1) :2 = 210
=> 101x + 5050 = 210
=> 101x = 210 - 5050
=> 101x = -4840
=> x = -4840 : 101
=> x = -4840/101
tính
x+(x+1)+(x+2)+...+(x+100)=210
(100x) + ( 1+2+...+100 ) = 210
(100x) + 5050 = 210
100x = 210 - 5050 = -4840
x = -4840 : 100
x = -48,4
x+120-210+111+x=1002
ta co: x+120-210+111+x=1002
2x+120-210+111=10000
2x=10000-111+210-120
2x=9979
x=9979:2
x=4989,5
Tìm các số nguyên x biết: a) (-8).x = (-10).(-2) - 4; b) (-9).x + 3 = (-2).(-7) + 16; c) 22.x+100 = 210; d) (-12).x - 34 = 2
bài 1:tìm x biết
a,(125-x)+25=98
b,100:(x+20)=68:34
c,(3.x+12).5=25.4-10
d,210:(2.x-3)-20=10
a) (125 - x) + 25 = 98
125 - x = 98 - 25
125 - x = 73
x = 125 - 73
x = 52
b) 100 : (x + 20) = 68 : 34
100 : (x + 20) = 2
x + 20 = 100 : 2
x + 20 = 50
x = 50 - 20
x = 30
c) (3x + 12) . 5 = 25 . 4 - 10
(3x + 12) . 5 = 100 - 10
(3x + 12) . 5 = 90
3x + 12 = 90 : 5
3x + 12 = 18
3x = 18 - 12
3x = 6
x = 6 : 2
x = 3
d) 210 : (2x - 3) - 20 = 10
210 : (2x - 3) = 10 + 20
210 : (2x - 3) = 30
2x - 3 = 210 : 30
2x - 3 = 70
2x = 70 + 3
2x = 73
x = 73/2
a, ( 125 - x ) + 25 = 98
⇒ 125 - x = 73
⇒ x = 52.
Vậy..
b, 100 : ( x + 20 ) = 68 : 34
⇒ 100 : ( x + 20 ) = 2
⇒ x + 20 = 50
⇒ x = 30
Vậy...
c, ( 3 . x + 12 ) . 5 = 25 . 4 - 10
⇒ ( 3 . x + 12 ) . 5 = 90
⇒ 3 .x + 12 = 18
⇒ 3x = 6
⇒ x = 2.
Vậy...
d, 210 : ( 2 .x - 3 ) - 20 = 10
⇒ ( 2 .x - 3 ) - 20 = 21
⇒ 2x - 3 = 41
⇒ 2x = 44
⇒ x = 22.
Vậy..
Cho mk chỉnh lại câu cuối:
d, 210 : ( 2 .x - 3 ) - 20 = 10
⇒ 210 : ( 2 .x - 3 ) = 30
⇒ 2 . x - 3 = 7
⇒ 2x = 10
⇒ x = 5.
Vậy..
100 x 210 = ?
200 - 18 : (372:3.x-1)-28=166
(100-99+98-97+96-95+...+4-3+2-1):50+2010-12.x=91
x-(31/3+31/15+31/35+31/63+31/99+31/143)=9/13
#)Giải :
\(200-18:\left(372:3x-1\right)-28=166\)
\(\Leftrightarrow200-18:\left(372:3x-1\right)=194\)
\(\Leftrightarrow18:\left(372:3x-1\right)=6\)
\(\Leftrightarrow372:3x-1=3\)
\(\Leftrightarrow3x-1=124\)
\(\Leftrightarrow3x=125\)
\(\Leftrightarrow x=\frac{125}{3}\)
200 - 18 : (372 : 3 . x - 1) - 28 = 166
=> 200 - 18 : (372 : 3.x - 1) = 166 + 28
=> 200 - 18 : (372 : 3.x) - 1) = 194
=> 18 : (372 : 3.x - 1) = 200 - 194
=> 18 : (372 : 3.x - 1) = 6
=> 372 : 3.x - 1 = 18 : 6
=> 372 : 3.x - 1 = 3
=> 372 : 3.x = 3 + 1
=> 372 : 3.x = 4
=> 3.x = 372 : 4
=> 3.x = 93
=> x = 93 : 3
=> x = 31
#)Next:
\(\left(100-99+98-97+...+2-1\right):50+2010-12x=91\)
\(\Leftrightarrow\left[\left(100-99\right)+\left(98-97\right)+...+\left(2-1\right)\right]:50+2010-12x=91\)
\(\Leftrightarrow\left[1+1+...+1\right]:50+2010-12x=91\)
\(\Leftrightarrow50:50+2010-12x=91\)
\(\Leftrightarrow1+2010-12x=91\)
\(\Leftrightarrow2011-12x=91\)
\(\Leftrightarrow12x=1920\)
\(\Leftrightarrow x=160\)
bài 15: tìm x
a) (x - 25 ) - 175 = 0
b) 485 - ( 6 . x + 60 ) = 5
c) ( x - 31 ) - 68 = 0
d) 274 - ( 9 . x + 18 ) = 4
e) 315 + ( 135 - x ) = 450
f) 346 + ( 210 - x ) = 556
g) 442 + ( 420 - x ) = 860
h) 107 + (320 - x ) = 317
Tìm x thuộc z biết:
a. x.(x+6)=0
b. 11x+210=100
c. (-8)x=(-5).(-7)-3
d. (-9)x+3=(-2).(-7)+16