tính
28.112-28.12+31
=28.(112-12)+31
=28.100+31
=2800+31
=2831
tim x
42 + 2(x-7) =128
2(x-7)=86
x-7=43
x=50
Tính nhanh :
a, 28.112-28.12+31
=28.(112-12)+31
=28.100+31
=2800 + 31
=2831
tìm x :
a, 42+2.(x-7)=128
2.(x+7)=128-42
2.(x+7)=86
x+7=86:2
x+7=43
x=43-7
x=36
Vậy x=36
Tính nhanh : 28.112-28.12+31 Tìm x : 42+2.(x-7)=128
=28.(112-12)+31 2.(x-7)=128-42
=2800+31 2.(x-7)=86
=2831 x-7=86:2
x-7=43
x=43+7
x=50
tk cho mình nhé
Cho tôi chữa lại bài tìm x nhìn nhầm đề :
42+2(x-7)=128
2(x-7)=128-42
2(x-7)=86
x-7=86:2
x-7=43
x=43+7
x=50
Vậy x=50
\(28.112-28.12+31\)
\(28.\left(112-12\right)+31\\ =28.100+31\)
\(=2800+31\)
\(=2831\)
\(42+2\left(x-7\right)=128\)
\(2\left(x-7\right)=128-42\)
\(2\left(x-7\right)=86\)
\(x-7=86:2\)
\(x-7=43\)
\(x=43+7=50\)
Hok tôt
+) \(28.112-28.12+31\)
\(=28.\left(112-12\right)+31\)
\(=28.100+31\)
\(=2800+31\)
\(=2831\)
+) \(42+2\left(x-7\right)=128\)
\(\Rightarrow2\left(x-7\right)=128-42\)
\(\Rightarrow2\left(x-7\right)=86\)
\(\Rightarrow x-7=86:2\)
\(\Rightarrow x-7=43\)
\(\Rightarrow x=43+7\)
\(\Rightarrow x=50\)
Vậy x = 50
_Chúc bạn học tốt_
a) 28.112-28.12+31
=28.(112-12+31)
=28.131
=3668
a) 42+2( x-7)=128
2(x-7) =128-42
2(x-7) = 86
(x-7) =86:2
(x-7) =43
x =43+7
x =50
chúc bạn học tốt ~~
