Question

If f(x) = 3x - 5 and g(x) = 7x + 2, what is f(x) x g(x)

Answer 1

21x + 1

Explanation:

f[g(x)]

= f(7x + 2)

= 3(7x + 2) - 5

= 21x + 6 - 5

= 21x + 1

Answer 2

Answer

21x^2 - 29x - 10

Explanation

f(x) • g(x)

Same as

(3x - 5) • (7x + 2)

Same as

3x(7x + 2) - 5(7x + 2)

21x^2 + 6x - 35x - 10

Collect like terms

21x^2 - 29x - 10