( 4x + 5 ) : 3 - 121 : 11 = 4
( 4x + 5 ) : 3 - 11 = 4
( 4x + 5 ) : 3 = 4 + 11
( 4x + 5 ) : 3 = 15
4x + 5 = 15 x 3
4x + 5 = 45
4x = 45 - 5
4x = 40
x = 40 : 4
x = 10
( 4x + 5) : 3 - 12 : 11 = 4
( 4x + 5) : 3 - 12 = 4 x 11 = 44
( 4x + 5) : 3 = 44 + 12 = 56
4x + 5 = 56 x 3 = 168
4x = 168 - 5 = 163
x = 163 : 4
x = ....
< Đề sai thì phải >
\(\left(4x+5\right):3-12:11=4\)
\(\left(4x+5\right):3-12:11=4+\frac{12}{11}\)
\(\left(4x+5\right):3=\frac{56}{11}\)
\(\left(4x+5\right):3=\frac{56}{11}\cdot3\)
\(4x+5=\frac{168}{11}\)
\(4x=\frac{168}{11}-5\)
\(4x=\frac{113}{11}\)
\(x=\frac{113}{11}:4\)
\(x=\frac{113}{44}\)