Tìm X biết
10+2x=45:43
Tìm số nguyên x , biết
10 - 2 ( 4 - 3x) = -4
c) -12 + 3(-x + 7 ) = -18
-45 : 5 . (-3 - 2x) = 3
3x - 28 = x +36
(-12)2 . x = 56 + 10 . 13x
a.
\(10-2\left(4-3x\right)=-4\)
\(\Leftrightarrow2\left(4-3x\right)=10+4\)
\(\Leftrightarrow2\left(4-3x\right)=14\)
\(\Leftrightarrow4-3x=7\)
\(\Leftrightarrow3x=-3\)
\(\Leftrightarrow x=-1\)
b.
\(-12+3\left(-x+7\right)=-18\)
\(\Leftrightarrow3\left(-x+7\right)=-18+12=-6\)
\(\Leftrightarrow-x+7=-6:3=-2\)
\(\Leftrightarrow x=9\)
c.
\(-45:5.\left(-3-2x\right)=3\)
\(\Leftrightarrow-9.\left(-3-2x\right)=3\)
\(\Leftrightarrow-3-2x=-\dfrac{1}{3}\)
\(\Leftrightarrow2x=-\dfrac{8}{3}\)
\(\Leftrightarrow x=-\dfrac{4}{3}\notin Z\left(loại\right)\)
Câu này em ghi sai đề?
d.
\(3x-28=x+36\)
\(\Leftrightarrow2x=28+36\)
\(\Leftrightarrow2x=64\)
\(\Leftrightarrow x=32\)
e.
\(\left(-12\right)^2.x=56+10.13x\)
\(\Leftrightarrow144x=56+130x\)
\(\Leftrightarrow144x-130x=56\)
\(\Leftrightarrow14x=56\)
\(\Leftrightarrow x=4\)
Tìm số tự nhiên x biết: 10 + 2x = 45:43
10 + 2x = 45 : 43
10 + 2x = 45 - 3
10 + 2x = 42
10 + 2x = 16
2x = 16 - 10
2x = 6
x = 6 : 2
x = 3
Vậy x = 3
Tìm số tự nhiên x biết: 10 + 2x = 45:43
B1: Tìm x biết:
a, 3x = 81 b, 5 . 4x = 80
c, 2x = 45 : 43 d, 3 . 2x+1 - 32 = 15
e, 5x-1 + 311 : 39 = 34 h, 43 . 4x-1 = 64
a: 3x=81
nên x=27
b: \(5\cdot4^x=80\)
\(\Leftrightarrow4^x=16\)
hay x=2
c: \(2^x=4^5:4^3\)
\(\Leftrightarrow2^x=2^4\)
hay x=4
Tìm x, biết:
a, 70 - 5 ( x - 3 ) = 45
b, 10 + 2 x = 4 5 : 4 3
c, 60 - 3 x - 2 = 51
d, 4 x - 20 = 2 5 : 2 3
a, 70 - 5 ( x - 3 ) = 45
⇔ 5 . x - 3 = 70 - 45
⇔ 5 x - 3 = 35
⇔ x - 3 = 35 : 5 ⇔ x - 3 = 7
⇔ x = 10
b, 10 + 2 x = 4 5 : 4 3
⇔ 10 + 2 x = 4 2 ⇔ 10 + 2 x = 16
⇔ 2 x = 4 ⇔ x = 2
c, 60 - 3 x - 2 = 51
⇔ 3 x - 2 = 60 - 51
⇔ 3 x - 2 = 9
⇔ x - 2 = 3 ⇔ x = 5
d, 4 x - 20 = 2 5 : 2 3
⇔ 4 x - 20 = 2 2 ⇔ 4 x - 20 = 4
⇔ 4 x = 24 ⇔ x = 6
Tìm số nguyên x:
a) -2x -(x-17)=34 -(-x+25)
b) 17x -(16x-37)=2x+43
c) -2x - 3.(x-17)=34-2(-x+25)
d) 17x + 3.(-16-37)=2x + 43 -4x
e) {-3x + 2.[45 - x - 3(3x + 7)-2x] + 4x}=55
Giúp mik vs:33
a,-2x -(x-17)=34-(-x+25)
-2x-x+17=34+x-25
-3x+17=9+x
-3x-x=9-17
-4x=-8
-->4x=8
x=8:4
x=2
Vậy x=2
b,17-(16x-37)=2x+43
17-16x+37=2x+43
20-16x=2x+43
-16x-2x=43-20
-18x=23
x=23:(-18)
x=23/-18
Mà x là số nguyên nên --> x thuộc tập rỗng
c,-2x-3.(x-17)=34-2(-x+25)
-2x-3x+51=34-2.(-x)-25
-5x+51=9-(-2).x
-5x+(-2).x=9-51
-7x=-42
7x=42
x=42:7
x=6
Vậy x=6
Tìm x biết:
a, 17-(43-|x|)=45
b, (x-2).(x+15)=0
c, 2x^2-3=29
a.\(17-\left(43-\left|x\right|\right)=45\)
\(\Leftrightarrow43-\left|x\right|=17-45\)
\(\Leftrightarrow43-\left|x\right|=-28\)
\(\Leftrightarrow\left|x\right|=43+28\)
\(\Leftrightarrow\left|x\right|=71\)
\(\Leftrightarrow x\in\left\{-71;71\right\}\)
b. \(\left(x-2\right)\left(x+15\right)=0\Leftrightarrow x\in\left\{2;-15\right\}\)
c. \(2x^2-3=29\)
\(\Leftrightarrow2x^2=29+3\)
\(\Leftrightarrow2x^2=32\)
\(\Leftrightarrow x^2=32\div2\)
\(\Leftrightarrow x^2=16\)
\(\Leftrightarrow x^2=4^2=\left(-4\right)^2\)
Vậy x = 4 hoặc x = 4
tìm số ngyên x :
a) -2x-(x-17)=34-(-x+25)
b) 17x-(-16x-37)=2x+43
c) -2x-3.(x-17)=34-2(-x+25)
d) 17x+3.(-16x-37)=2x+43-4
e) {-3x+2.[45-x-3(3x+7)-2x]+4x}=55
g)103-57; [-2.(2x-1)2 -(-9)0 ] =-106
tìm số ngyên x :
a) -2x-(x-17)=34-(-x+25)
-2x - x +17 =34 + x -25
-3x + 17 =9 +x
-3x + 17 - 9 -x=0
-4x + 8 = 0
-4x = -8
x =2
b) 17x-(-16x-37)=2x+43
17x + 16x + 37 = 2x +43
33x + 37 = 2x +43
33x + 37 - 2x -43=0
31x - 6 =0
31x = 6
x=6/31
tìm số nguyên x
-2x-(x-17)=34-(-x+25)
17x-(-16x-37)=2x =43
-2x-3.(x-17)=34-2(-x+25)
17x+3.(-16x-37)=2x+43
{-3x+2.[45-x-3(3x+7)-2]+4}
55-103-57:[-2.(2x-1)2.(-9)0=-106
Tìm số tự nhiên x:
a) 2x : 4 = 16
b) 4x-3 = 256
c) (2x + 1)3 = 343
d) 10 + 2x = 45 : 43
a) \(2^x:4=16\\ \Rightarrow2^x=64\\ \Rightarrow2^x=2^6\\ \Rightarrow x=6\)
b) \(4^{x-3}=256\\ \Rightarrow4^{x-3}=4^4\\ \Rightarrow x-3=4\\ \Rightarrow x=7\)
c) \(\left(2x+1\right)^3=343\\ \Rightarrow\left(2x+1\right)^3=7^3\\ \Rightarrow2x+1=7\\ \Rightarrow x=3\)
d) \(10+2x=4^5:4^3\\ \Rightarrow10+2x=16\\ \Rightarrow x=3\)
a,2^x:4=16
2^x=16.4=64
2^x=2^6
=>x=6
b,4^x-3=256
4^x-3=4^4
=>x-3=4
x=4+3=7
c,(2x+1)^3=343
(2x+1)^3=7^3
=>2x+1=7
2x=7-1=6
x=6:2=3
d,10+2x=4^5:4^3
10+2x=4^2=16
2x=16-10=6
x=6:2=3