2x-138=72
2x - 138= 72
2x-138=72
2x=72+138
2x=110
x=110:2
x=55
vậy x=55
2x - 138 = 72
=> 2x = 72 + 138
=> 2x = 210
=> 2x = 210
=> x = 210 : 2
=> x = 105
72-x=50
2x-138=72
5.3x = 135
\(72-x=50\\ \Rightarrow x=22\)
\(2x-138=72\\ \Rightarrow2x=210\\ \Rightarrow x=105\)
\(5.3^x=135\\ \Rightarrow3^x=27\\ \Rightarrow3^x=3^3\\ \Rightarrow x=3\)
72−x=50⇒x=2272−x=50⇒x=22
2x−138=72⇒2x=210⇒x=1052x−138=72⇒2x=210⇒x=105
5.3x=135⇒3x=27⇒3x=33⇒x=3
Bài 1: Tìm x là STN biết:
a) 4(x - 3) = 72 - 20220
b) 123 - 5 x (x + 4) = 38
c) 2x - 138 = 23.32
Mong giúp đỡ ạ!!!
a: =>4(x-3)=49-1=48
=>x-3=12
=>x=15
b: =>123-5(x+4)=38
=>5(x+4)=123-38=85
=>x+4=17
=>x=13
c: =>2x-138=9*8=72
=>2x=72+138=210
=>x=105
câu2
a.2x-138=72
b.3^2-3x=6^6:6^5
c.(64-4x).3=24
d.3^x.6-39=123
a.2x - 138 =72
\(\Leftrightarrow\)2x = 210 \(\Leftrightarrow\)x= 105
b.32 - 3x =66 : 65
\(\Leftrightarrow\)9 - 3x =6 \(\Leftrightarrow\)3x =3 \(\Leftrightarrow\)x=1
c.( 64 -4x).3 =24
\(\Leftrightarrow\)64-4x =8 \(\Leftrightarrow\)4x = 56 \(\Leftrightarrow\)x=14
d.3x.6 - 39 =123
\(\Leftrightarrow\) 3x . 6 = 162 \(\Leftrightarrow\)3x =27 \(\Leftrightarrow\)x =3
Bài toán: 138 - 72
Chú ý:
không được ghi ở trên(138-72=66)
461 - 76 =
413 - 86 =
952 - 99 =
138 - 72 = 66
461 - 76 = 385
413 - 86 = 327
952 - 99 = 853
Bài toán: 138 - 72
461 - 76 =
413 - 86 =
952 - 99 =
Toán lớp 2
138 - 72 = 66
461 - 76 = 385
413 - 86 = 327
952 - 99 = 853
3) 287 + 121 + 513 + 79
4) 17.34 + 17.39 + 27.17
5) 4. 52 – 64: 42
6) 25 . 101 – 25 .1010
7) 72 + [ 62 – ( 102 – 4 . 16 )]
8) 2x – 138 = 23. 32
9) [120 : 4 – (23 -17) . 5]. 20212022
2.x-138=72
2 . x - 138 = 72
2 . x = 72 + 138
2 . x = 210
x = 210 : 2
x = 105
2x-138=72
=> 2x = 72+138
2x = 200
x = 200/2
=100
So sánh
a) 138.(-10) với 0
b) 627.(-3) với 627
c) (-72).8 với -72
a)138 . ( − 1 0 ) < 0
b ) 627 . ( − 3 ) < 627
c ) ( − 72 ) . 8 < − 72
Tim so tu nhien x biet :
A,(2600+6400)-3×x=1200
B,[(6×x-72):2-84].28=5628
C,2x-138=2^3÷3^2
d,42x=39×42-37×42
Dup minh nhe
\(a,\left(2600+6400\right)-3\times x=1200\)
\(9000-3\times x=1200\)
\(3\times x=9000-1200\)
\(3\times x=7800\)
\(x=7800:3\)
\(x=2600\)
\(b,\left[\left(6\times x-72\right):2-84\right]\times28=5628\)
\(\left(6\times x-72\right):2-84=5628:28\)
\(\left(6\times x-72\right):2-84=201\)
\(\left(6\times x-72\right):2=201+84\)
\(\left(6\times x-72\right):2=285\)
\(6\times x-72=285\times2\)
\(6\times x-72=570\)
\(6\times x=570+72\)
\(6\times x=642\)
\(x=107\)
\(c,2x-138=2^3:3^2\)
\(2x-138=\frac{8}{9}\)
\(2x=\frac{8}{9}+138\)
\(2x=\frac{1250}{9}\)
\(x=\frac{1250}{9}:2\)
\(x=\frac{625}{9}\)
\(d,42x=39\times42-37\times42\)
\(42x=42\times\left(39-37\right)\)
\(42x=42\times2\)
\(42x=84\)
\(x=2\)