2006-12-12 13:09:32 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
3 n = 7n -20
-4 n = -20
n = 20/4
n = 5
2006-12-12 13:12:16 · answer #1 · answered by Anonymous · 0⤊ 0⤋
n=5
2006-12-12 13:10:58 · answer #2 · answered by StressedSweetie 2 · 1⤊ 0⤋
n=5
2006-12-12 13:10:57 · answer #3 · answered by zakawitz 1 · 1⤊ 0⤋
3n + 7 = 7n - 13
Ok I'll start by saying you can move all "like terms" to one side of the equation, then changing their sign.
3n - 7n = - 13 - 7
Or here it is step by step.
3n + 7 = 7n - 13
Yyou can either subtract 3n OR 7n from both sides, but let's subtract 3n because it's easier.
7 = 4n - 13
WHAT YOU DO ON ONE SIDE OF AN EQUATION, YOU MUST ALWAYS DO THE SAME ON THE OTHER SIDE.
7 = 4n - 13
Add 13 on both sides. (We add this time because negative 13 plus 13 equals zero.)
20 = 4n
Subtract by 4 on both sides.
5 = n
Next time, try to do your own homework, or else McDonald's awaits.
2006-12-12 13:17:09 · answer #4 · answered by Anonymous · 0⤊ 0⤋
First you have to combine like terms.
3n+7 = 7n-13
subtract 3n from both sides:
7 = 4n - 13
Then add 13 to each side
20 = 4n
Then, to solve for n you have to divide by 4
20/4 = 4n/4
This cancels out the 4's
5 = n And thats the answer
2006-12-12 13:14:18 · answer #5 · answered by J. R 3 · 0⤊ 0⤋
-7 from both sides and -7n from both to get, -4n=-20. divide by -4 to get n=5
2006-12-12 13:11:51 · answer #6 · answered by loveboatcaptain 5 · 1⤊ 0⤋
if n=3.5
2006-12-12 13:10:49 · answer #7 · answered by Anonymous · 0⤊ 2⤋