a) 7^2.5-(2x+1)=630:9
b) (10-4x)+120:2^3=17
c) [124-(20-4X)]:30+7=11
d) |2x-5|=1
nhớ ghi đầy đủ bước nhá
Tìm x,biết:
a,72,5-(2x+1)=630:9
b,(10-4x)+120:23=17
c,[124-(20-4x):30+7=11
d,/2x-5/=1
a) 72,5 - (2x + 1) = 630 : 9
⇒ 72,5 - (2x + 1) = 70
⇒ 2x + 1 = 2,5
⇒ 2x = 1,5
⇒ x = 0,75
b) (10 - 4x) + 120 : 23 = 17
⇒ (10 - 4x) + 120 : 8 = 17
⇒ (10 - 4x) + 15 = 17
⇒ 10 - 4x = 2
⇒ 4x = 8
⇒ x = 2
Vậy x = 2
c) [124 - (20 - 4x)] : 30 + 7 = 11
⇒ [124 - (20 - 4x)] : 30 = 4
⇒ 124 - (20 - 4x) = 120
⇒ 20 - 4x = 4
⇒ 4x = 16
⇒ x = 4
Vậy x = 4
tìm x biết:a, 72.5-(2x+1)=630:9 b, (10-4x)+120:23=17
72 x 5-(2x+1)=630:9
<=> 49 x 5-2x-1=70
<=> 245-2x-1=70
<=> -2x+244=70
<=> -2x=-174
<=> x=87
tìm x biết:
a, 72.5-(2x+1)=630:9
49.5-(2x+1)=70
245-(2x+1)=70
2x+1=245-70
2x+1=175
2x=175-1
2x=174
x=174:2
x=87
Vậy x=87
b, (10-4x)+120:23=17
(10-4x)+120:8=17
(10-4x)+15=17
10-4x=17-15
10-4x=2
4x=10-2
4x=8
x=8:4
x=2
Vậy x=2
a, 72.5-(2x+1)=630:9
\(\Leftrightarrow\) 49.5-(2x+1)=70
\(\Leftrightarrow\) 245 - (2x+1) = 70
\(\Leftrightarrow\) 2x + 1 = 245 - 70
\(\Leftrightarrow\) 2x + 1 = 175
\(\Leftrightarrow\) 2x = 175 - 1
\(\Leftrightarrow\) 2x = 174
\(\Leftrightarrow\) x = 174 : 2
\(\Leftrightarrow\) x = 87.
Vậy x = 87.
b, (10-4x)+120:23=17
\(\Leftrightarrow\) (10-4x)+120:8 = 17
\(\Leftrightarrow\) (10-4x)+15 = 17
\(\Leftrightarrow\) 10 - 4x = 17 - 15
\(\Leftrightarrow\) 10 - 4x = 2
\(\Leftrightarrow\) 4x = 10 - 2
\(\Leftrightarrow\) 4x = 8
\(\Leftrightarrow\) x = 8 : 4
\(\Leftrightarrow\) x = 2
Vậy x = 2.
# HOK TỐT #
a, 2(x - 5) + 3(2 - 3x) = 5x + 7
b, 3x - 5(x - 2) + 7 = 4x - 12
c, 1/5×8 + 1/8×11 + 1/11×14 +...+ 1/x(x+3) = 101/1540
d, ( 3/1×2×3 + 3/2×3×4 + 3/3×4×5 +...+ 3/8×9×10 ).x = 22/15
Thanks you so much!
Nhớ ghi đầy đủ các bước làm ra nhá!
\(2\left(x-5\right)+3\left(2-3x\right)=5x+7\)
\(\Leftrightarrow2x-10+6-9x=5x+7\)
\(\Leftrightarrow\left(2x-9x\right)+\left(6-10\right)=5x+7\)
\(\Leftrightarrow-7x-4=5x+7\)
\(\Leftrightarrow-7x-5x=4+7\)
\(\Leftrightarrow-12x=11\)
\(\Leftrightarrow x=\frac{-11}{12}\)
\(3x-5\left(x-2\right)+7=4x-12\)
\(\Leftrightarrow3x-5x-10+7=4x-12\)
\(\Leftrightarrow\left(3x-5x\right)-\left(10-7\right)=4x-12\)
\(\Leftrightarrow-2x-3=4x-12\)
\(\Leftrightarrow-2x-4x=3-12\)
\(\Leftrightarrow-6x=-15\)
\(\Leftrightarrow x=\frac{-15}{-6}=\frac{5}{2}\)
\(\frac{1}{5.8}+\frac{1}{8.11}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)
\(\Leftrightarrow\frac{3}{5.8}+\frac{3}{8.11}+...+\frac{3}{x\left(x+3\right)}=\frac{101}{1540}.3\)
\(\Leftrightarrow\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{x}-\frac{1}{x+3}=\frac{303}{1540}\)
\(\Leftrightarrow\frac{1}{5}-\frac{1}{x+3}=\frac{303}{1540}\)
\(\Leftrightarrow\frac{5}{5\left(x+3\right)}=\frac{1}{5}-\frac{303}{1540}\)
\(\Leftrightarrow\frac{5}{5x+15}=\frac{308}{1540}-\frac{303}{1540}\)
\(\Leftrightarrow\frac{5}{5x+15}=\frac{5}{1540}\)
\(\Leftrightarrow5x+15=1540\)
\(\Leftrightarrow5x=1540-15\)
\(\Leftrightarrow5x=1525\)
\(\Leftrightarrow x=1525\div5\)
\(\Leftrightarrow x=305\)
tìm x,biết:
a, 72.5-(2x+1)=630:9
b, (10-4x)+120:23=17
Bạn nào làm nhanh mình tick nha.
a,<=> 145-2x-1=70
<=> 2x=74
<=> x=37
b, <=> 10-4x+15=17
<=> 4x=8
<=> x=2
\(7^2\cdot5-\left(2x+1\right)=630\div9\)
\(49\cdot5-\left(2x+1\right)=70\)
\(245-\left(2x+1\right)=70\)
\(2x+1=245-70\)
\(2x+1=175\)
\(2x=175-1\)
\(2x=174\)
\(x=174\div2\)
\(x=87\)
\(\left(10-4x\right)+120\div2^3=17\)
\(\left(10-4x\right)+120\div8=17\)
\(\left(10-4x\right)+15=17\)
\(10-4x=17-15\)
\(10-4x=2\)
\(4x=10-2\)
\(4x=8\)
\(x=8\div4\)
\(x=2\)
Tìm x biet:
a,5/2x+x=32/15
b,x-7/2x=-32/15
c,-7/3x-7/4x+11/3=18/5
d,-5/6-3x=2/3
e,2x-5/9=-2/3
f,1/2-2/3x=7/12
g,7-|2x-3|=4
h,(19x+2.5^2):14=(13-8)^2-4^2
i,3/4x-2/3=2/7.1/6+5/7.1/6
k,(x+1/2).(2/3-2x)=0
l,x/2013-1/10-1/15-1/21-........-1/120=5/8
1.tìm x
a) 4.(2x + 7) - 3.(3x - 2) = 24
b) 2.(x - 1) + 3.(x - 2) = x - 4
c) [124 - (20 - 4x)] : 30 + 7 = 11
a. 4(2x+7)-3(3x-2)=24
=> 8x+28-9x+6=24
=> -x+34=24
=> -x=-10=> x=10
b. 2(x-1)+3(x-2)=x-4
=> 2x-2+3x-6=x-4
=> 5x-8=x-4
=> 5x-x=-4+8
=> 4x=4=> x=1
c. [124-(20-4x)]:30+7=11
=> (124-20+4x):30=4
=> (104+4x):30=4
=> 104+4x=120
=> 4x=96 => x=24
[124-(20+4x)]:30+7=11
Ai nhanh mik k cho
nhớ giải đầy đủ nha
[124-(20+4x)]:30+7=11
[124-(20+4x)]:30 = 11-7
[124-(20+4x)]:30 = 4
[124-(20+4x)] =4 x 30
[124-(20+4x)] =120
[124-20-4x] =120
104-4x = 120
-4x = 120-104
-4x = 16
x = -4
124-20-4x:30+7=11
104-120x+7=11
-120x=11-104-7
-120x=-100
x=5/6
~Tk mình nha!!!>.<~
210-5x=200
210-5(x-10)=200
450:[41-(2x-5)]= 3^2.5
210:x-10=20
(5x-39).7+3=80
(2x+1):7=2^2.3^2
lưu ý:^ là mũ
VD3^2=ba mũ hai
làm đầy đủ hộ mình nha
a)210-5x=200
5x=210-200
5x=10
x=10:2
x=5
B)210-5(x-10)=200
5(x-10)=210-200
5(x-10)=10
x-10=10:5=2
x=2+10=12
c)450:[41-(2x-5)]=3 mũ 2 .5
450:[41+5-2x]=45
41+5-2x=450:45
41+5-2x=10
2x=36
x=18
D)210:x-10=20
210:x=20+10
210:x=30
x=210:30
x=7
E)(5x-39).7+3=80
(5x-39).7=77
5x-39=11
5x=50
x=10
F(2x+1):7=2 mũ 2 nhân 3 mũ 2
(2x+1):7=36
2x+1=252
2x=251
x=251/2
a) x+(-5)=-(-7)
b) x-8=-10
c) 2x+20=-22
d) -(-30)-(-x)=13
nhớ nghi đầy đủ các bước giải nha
a) x + (-5) = -(-7)
x - 5 = 7
x = 7 + 5
x =12
b) x - 8 = (-10)
x = (-10) + 8
x = -2
c) 2x + 20 = -22
2x = -22 - 20
2x = (-22) + (-20)
2x = -42
x = -42 : 2
x = -21
d) -(-30) - (-x) = 13
30 + x = 13
x = 13 - 30
x =13 + (-30)
x = -17
X CHO MK NHA
a) x+(-5)=-(-7)
x - 5 = 7
x = 7+5
x=12
b) x-8=-10
x = -10 +8
x=-2
c) 2x+20=-22
2x=-22-20
2x=-42
x=-42:2
x=-21
d) -(-30)-(-x)=13
30 +x=13
x=13-30
x=-17
Chúc bạn học tốt!
a, x + (-5) = -(-7)
x + (-5) = 7
x = 7 - (-5)
x = 7 + 5
x = 12
Vậy x = 12
b, x - 8 = -10
x = -10 + 8
x = -2
Vậy x = -2
c, 2x + 20 = -22
2x = -22 - 20
2x = -42
x = (-42) : 2
x = -21
Vậy x = -21
d, -(-30) -(-x) = 13
30 + x = 13
x = 13 - 30
x = -17
Vậy x =-17
Hok tốt !