Question

The domain of f(x) = 7x + 4 is {-1 < x < 4}. Which integer is not in the range?

1. all of them are in the range
2. 26
3. 21
4. 17
5. 12​

Answer 1

1. all of them are in the range

Explanation:

Since -1 < x < 4

then -1 (7) < 7x < 7(4)

- 7 < 7x < 28

-7 + 4 < 7x + 4 < 28 + 4

-3 < 7x + 4 < 32

SInce all the options are within the range between -3 and 32 then the answer is 1.