Question

2(4n + 10)
a.4n + 10 + 4n + 10 =?
b. 8n + 20 =?
c.28n
d. 2n + 5 + 2n + 5 ?

Answer 1

2(4n + 10) = 2·4n + 2·10 = 8n + 20.

Now evaluate the choices:
a. 4n + 10 + 4n + 10 = 8n + 20 — equal (yes).
b. 8n + 20 — equal (yes).
c. 28n — not equal (unless 20 somehow equals 20n, which it doesn't).
d. 2n + 5 + 2n + 5 = 4n + 10 — not equal (it's half of 8n + 20).