Question

If 3n+ 4n = 42, then n is
a. 4.
a. 2
c. 7.
D .21

Answer 1

n=6

Explanation:

3n+4n = 42

(3+4)n = 42

7n = 42

Dividing both sides by the coefficient of n, which is 7, we have

n = 42/7

n = 6

Answer 2

n = 6

Explanation:

First we would plug the values with n, starting with 4.

`3*4 + 4*4 = 28`

So A. is not an option

Now we try 2.

`3*2 + 4*2 = 14`

B is NOT an option

Now we try 7

`3*7 + 4*7 = 49`

Now we try 21

`3*21 + 4*21 = 147`

Now we check what was closest...7

so we try numbers less than 7

n is = to 6