a) 70 - 5 .(x -3 ) =45
5 . ( x - 3 ) = 70 - 45
5 . ( x - 3 ) = 25
x - 3 = 25 : 5
x - 3 = 5
x = 5 + 3
x = 8
b) 156 - ( x + 61 )+82
sai đề ( không có kết quả )
c) 10 +2 .x = 45 : 43
10 + 2 . x = 42 = 16
2 . x = 16 -10
2 . x = 6
x = 6 : 2
x = 3
d) [(10 - x ).2 +3 ];3 -2=13
[ ( 10 - x ) . 2 + 3 ] : 3 = 13 + 2
[ ( 10 - x ) . 2 + 3 ] : 3 = 15
[ ( 10 - x ) . 2 + 3 ] = 15 x 3
[ ( 10 - x ) . 2 + 3 ] = 45
( 10 - x ) . 2 = 45 - 3
( 10 - x ) . 2 = 42
10 - x = 42 : 2
10 - x = 21
x = 10 - 21
x = - 11
hok tốt
\(70-5\left(x-3\right)=45\)
\(5\left(x-3\right)=70-45\)
\(5\left(x-3\right)=25\)
\(x-3=\frac{25}{5}=5\)
\(x=5+3\)
\(x=8\)
\(10+2x=\frac{4^5}{4^3}\)
\(10+2x=4^2=16\)
\(2x=16-10\)
\(2x=6\)
\(x=\frac{6}{2}=3\)
\(\left[\left(10-x\right)2+3\right]:3-2=13.\)
\(\left[\left(10-x\right)2+3\right]:3=13+2=15\)
\(\left(10-x\right)2+3=15\cdot3\)
\(\left(10-x\right)2+3=45\)
\(\left(10-x\right)2=45-3=42\)
\(10-x=\frac{42}{2}=21\)
\(x=10-21\)
\(x=-11\)