Answer:

Step-by-step explanation:
The function is given.

To find : 
The input for the function f(x) is (a + 1).
Replace x with (a + 1).

Expand brackets.

Simplifying.

Answer:
discounted price = original price ( 1 - discount rate)
Step-by-step explanation:
Answer:
$22.68
Step-by-step explanation:
21×.08= 1.68
21+1.68=22.68
Total cost =$22.68
Answer:
4/5
Step-by-step explanation:
Answer:
The number is 7
Step-by-step explanation:
A number (x) multiplied by 8 = 8x divided by four gives;
8x ÷ 4 = 2x
The answer is seven more than the number i.e
2x = x + 7
2x - x = 7 , x = 7
So the number is 7.