(15-7x).3=15+9
(15-7x).3=24
(15-7x)=24:3
(15-7x)=8
7x=15-8
7x=7
x=7:7
x=1
vậy x=1
( 15 - 7x ) . 3 - 9 = 15
( 15 - 7x ) . 3 = 15+9
( 15 - 7x ) . 3 = 24
15 - 7x = 24:3
15 - 7x = 8
7x = 15-8
7x =7
x = 7:7
x = 1
Vậy x=1
[ 15 - 7x ].3 - 9 = 15
[15 - 7x] . 3 = 15 + 9
[ 15 - 7x].3 = 24
[ 15 - 7x] = 24 : 3
[ 15 - 7x] = 8
7x = 15 - 8
7x = 7
x = 7 : 7
x = 1
(15 - 7x ). 3 - 9 = 15 Học tốt ^^
(15 - 7x ) . 3 = 15 + 7
(15 - 7x) . 3 = 24
(15 - 7x ) = 24 : 3
15 - 7x = 8
7x = 15 - 8
7x = 7
x = 7 : 7
x = 1
Bài làm
\(\left(15-7x\right).3-9=15\)
\(\Leftrightarrow45-21x-9=15\Leftrightarrow24x=24\Leftrightarrow x=1\)