Is this the right answer?

Question

15 - 3n = 10

3n = 25

if its right, I'll take it from there. But if its not right, can you show me what i did wrong and how to actually do it? thanks

Answer 1

Solve for "n" in the equation...15 - 3n = 10

First: combine "like" terms - subtract 15 from both sides (when you move a term to the opposite side, always use the opposite sign).

15 -15 - 3n = 10-15

- 3n = 10 - 15

- 3n = - 5

Sec: isolate the "n" variable on one side (left) - divide both sides by (-3).

- 3n/-3 = - 5/-3

n = -5/-3

n = 5/3

Answer 2

not quite.

What you want is the terms containing the variable to be on one side and the numbers to be on the other. You have to maintain the equality to do this, though. You do things that "undo" what has been done to the variable, but must do them in the proper order.

In this example, you could first subtract 15 from both sides, to get the 3n by itself.
15 - 3n - 15 = 10 - 15
-3n = 10 - 15
-3n = -5

The n is still not by itself, though, so you undo the multiplication operation by dividing both sides by -3.

-3n = -5
-3n/-3 = -5/-3
1n = 5/3
n = 5/3

After awhile of doing this, you will not need the intermediate steps like -3n/-3 = -5/-3. You would just go straight from -3n = -5 to n = 5/3.

That is the key, though, you have to do the same thing to both sides, to maintain the equality sign.

Answer 3

Sorry, that's not right:

15 - 3n = 10
15 - 3n -10 = 10 - 10
5 - 3n = 0
5 - 3n + 3n = 0 + 3n
5 = 3n
n = 5/3

You probably messed up on your negatives somewhere.

Answer 4

n = 5/3

1. Subtract 15 from both sides: -3n = -5 > 3n = 5

2. Divide both sides by 3, n = 5/3

Answer 5

no, the answer is 5/3

15-3n=10
(first you have to subtract 15 on both sides, not add it)
15-3n=10
-15 -15
----- ------
-3n=-5
(then you divide -3 on both sides to isolate n)
-3n=-5
n=5/3

Answer 6

Nope Sorry.
First subtract 15 from both sides
-3n = -5
Then divide each side by -3
n = 5/3

Answer 7

no
15-3n=10 subtract 15 from each side
-3n=-5 divide both sides by -3
n=5/3

Answer 8

Not correct.

You are mixing your signs as you add and subtract on both sides of the equation.

Force your self to do the problem one step at a time adding and subtracting the same quantity on both sides of the equation.

Step 1 Add 3n to both sides
Step 2 Subtract 10 from both sides

Answer 9

15 - 3n = 10
15-10=3n
3n=5
n=5/3. you committed a mistake.chek

Answer 10

no it is not right this is the way to do it.
15-3n= 10
-3n = 10 -15
-3n = -5
n= 5/3