Three times the sum of 7 and a number is 24

The number is:

1

Step-by-step explanation:

3(7+a) = 24

3*7 + 3*a = 24

21 + 3a = 24

3a = 24 - 21

3a = 3

a = 3/3

a = 1

(f - g)(x) = 5x^3 - 3

step-by-step explanation:

rearrange these functions vertically, with like terms in separate columns:

f(x) = 5x^3 - 2

g(x) =         +1

now subtract, column by column:

(f - g)(x) = 5x^3 - 3