2006-11-16 08:57:36 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
15a = 3a(a+8)
First distribute the 3
15a = 9a + 24
Subtract 9a from each side
6a = 24
Divide both sides by 6
a = 4
You can easily check your answer by replacing a with 4.
15(4) = 3(3*4 +8)
60 = 3(12+8)
60 = 3(20)
60 = 60
Thus, a=4 is the correct answer.
2006-11-16 08:59:44 · answer #1 · answered by MsMath 7 · 3⤊ 3⤋
Distribute the 3(3a+8) so you get 15a=9a+24. Then subtract 9a from both sides which will give you 6a=24. Then all you do is divide each side by 9 which will give you a=4.
2006-11-16 09:03:08 · answer #2 · answered by Luekas 4 · 2⤊ 0⤋
15a = 3(3a+8)
15a = 3*3a + 8*3 (multiply whats in the brackets by 3)
15a = 9a + 24
6 a = 24 (subtract each side by 9)
a = 4 (divide each side by 6)
2006-11-16 08:59:49 · answer #3 · answered by Paul W 1 · 3⤊ 1⤋
15a = 3(3a+8)
15a = 9a+24
15a - 9a= 24 + 9a - 9a
6a/6=24/6
a = 4 !
2006-11-16 09:03:55 · answer #4 · answered by merviedz trespassers 3 · 2⤊ 0⤋
15a = 3(3a + 8) --- Multiply the right side "( )" by the 3...
15a = 9a + 24 --- Subtract 9a from both sides...
6a = 24 --- Divide both sides by 6...
a = 4
2006-11-16 09:00:43 · answer #5 · answered by Anonymous · 4⤊ 0⤋
let's see, it's been awhile, but I bet I can do it:
15a = 3(3a+8)
/ 3 / 3
5a = 3a + 8
- 3a - 3a
2a = 8
/2 /2
a = 4
2006-11-16 09:03:04 · answer #6 · answered by redlips1487 3 · 2⤊ 0⤋
15a=3(3a+8)
15a=9a+24
15a-9a=24
6a=24
a=4
2006-11-16 09:01:33 · answer #7 · answered by schizohamster 2 · 2⤊ 0⤋
First, you need to do the multiplication in the brackets. so..
15a=9a+24
Then subtract 9a from both sides to get your variable by itself. so...
6a=24
Finally divide both sides by 6 to get it down to just a on the left. so...
a=4
2006-11-16 09:07:56 · answer #8 · answered by higgy 2 · 2⤊ 0⤋
15a=3(3a+8)
3x3a+8
15a=9a+8
15a+9a=24
24/8=3
a=3
2006-11-16 09:01:17 · answer #9 · answered by softrosepetal05 2 · 1⤊ 2⤋