2007-02-25 03:22:34 · 12 answers · asked by sexililcheerleader4u2006 1 in Science & Mathematics ➔ Mathematics
3x+9=21
3x=21-9
3x=12
x=12 divided by 3
x=4
Hope this helps! =D
2007-02-25 03:31:55 · answer #1 · answered by ;) 3 · 1⤊ 0⤋
4
2007-02-25 03:30:21 · answer #2 · answered by DSNY BK13 2 · 1⤊ 0⤋
4
2007-02-25 03:27:23 · answer #3 · answered by ahmadhbhb 1 · 1⤊ 0⤋
4
2007-02-25 03:25:36 · answer #4 · answered by Ricky J. 6 · 1⤊ 0⤋
4
2007-02-25 03:25:19 · answer #5 · answered by mystery_me 4 · 1⤊ 0⤋
9 + 3x = 21
3x = 12
x = 4
2007-02-25 03:26:03 · answer #6 · answered by Bhajun Singh 4 · 1⤊ 0⤋
9+3n=21, -9, get 12=3n, divide by 3, and the # is 4
2007-02-25 04:44:54 · answer #7 · answered by dancin' chick 2 · 0⤊ 0⤋
9+3x=21
Subtract 9 from both sides
9-9+3x=21-9
Simplify
3x=12
Divide both sides by 3
3x/3=12/3
Simplify
x=4
Check your work by plugging answer into original problem
9+3(4)=21
9+12=21
21=21
Therefore x=4
2007-02-25 03:35:47 · answer #8 · answered by Michelle M 2 · 1⤊ 0⤋
9+3x=21
3x=12
x=4
2007-02-25 03:26:54 · answer #9 · answered by Diksha A 3 · 1⤊ 0⤋
3x+9=21
Subtract 9 from both sides:
3x=12
Divide 3 from both sides:
x=4
Check:
3(4)+9=21
12+9=21
21=21
2007-02-25 04:06:06 · answer #10 · answered by Anonymous · 0⤊ 0⤋