a) 54 + x - 65 + 3 = 12
54 + x - 65 = 9
54 + x = 74
x = 74 - 54
x = 20
b) x - 45 + 65 = 59
x - 45 = -6
x = -6 + 45
x = 39
\(a,54+x-65+3=12\)
\(\Leftrightarrow54+x-\left(65-3\right)=12\)
\(\Leftrightarrow54+x-62=12\)
\(\Leftrightarrow54-x=12+62\)
\(\Leftrightarrow54-x=74\)
\(\Leftrightarrow x=54-74\)
\(\Leftrightarrow x=-20\)
\(b,x-45+65=59\)
\(\Leftrightarrow x-\left(45-65\right)=59\)
\(\Leftrightarrow x-\left(-20\right)\)
\(\Leftrightarrow x+20=59\)
\(\Leftrightarrow x=59-20\)
\(\Leftrightarrow x=39\)
a) 54 + x - 65 + 3 = 12
54 + x -65 = 12 + 3 = 15
54 + x = 15 + 65 = 80
x = 80 - 54
x =26
b) x - 45 + 65 = 59
x - 45 = 59 - 65 = -6
x = - 6 + 45
x = 39
hok tốt .
a) \(54+x-65+3=12\)
\(\Rightarrow\left(54-65+3\right)+x=12\)
\(\Rightarrow-8+x=12\)
\(\Rightarrow x=12-\left(-8\right)\)
\(\Rightarrow x=20\)
Vậy x = 20
b) \(x-45+65=59\)
\(\Rightarrow x+\left(-45+65\right)=59\)
\(\Rightarrow x+20=59\)
\(\Rightarrow x=59-20\)
\(\Rightarrow x=39\)
Vậy x = 39
_Chúc bạn học tốt_
b, x - 45 + 65 = 59
=> x - 45 = 59 - 65
=> x - 45 = -6
=> x = -6 + 45
=> x = 39
kl....
a) 54 + x - 65 + 3 = 12
54 + x - 65 = 15
54 + x = 80
x = 26
a, 54 + x - 65 + 3 = 12
54 + x - 65 = 12 + 3
54 + x -65 = 15
54 + x = 65 + 15= 80
x= 80 - 54
x= 26
b, x- 45 + 65=59
x - 45 = 59 - 65 =-6
x= -6 + 45
x= 39
lớp 2 đã hok số âm rồi ak?
hok tốt
a) 54 + x - 65 + 3 = 12
x + ( 54 - 65 + 3 ) = 12
x + ( -8 ) = 12
x = 12 - ( -8 )
x = 20
b) x - 45 + 65 = 59
x - 45 = 59 - 65
x - 45 = -6
x = - 6 + 45
x = 39
a) 54 + x - 65 + 3 = 12
x + ( 54 - 65 + 3 ) = 12
x + ( -8 ) = 12
x = 12 - ( -8 )
x = 20
b) x - 45 + 65 = 59
x - 45 = 59 - 65
x - 45 = -6
x = - 6 + 45
x = 39
a)
54 + x - 65 + 3 = 12
x + ( 54 - 65 + 3 ) = 12
x + ( -8 ) = 12
x = 12 - ( -8 )
x = 20
b)
x - 45 + 65 = 59
x - 45 = 59 - 65
x - 45 = -6
x = - 6 + 45
x = 39
