Question

Simplify a × 3a3b.

A. 6a4b2
B. 2a4b7
C. 4a2b2
D. 3a4b

Answer 1

$Use:a^n\cdot a^m=a^{n+m}\\\\a\cdot3a^3b=3a^{1+3}b=3a^4b\\\\Answer:\boxed{D.\ 3a^4b}$

Answer 2

Answer:

D. $3a^4b$

Step-by-step explanation:

We have: $a.3a^3b$ in order to simplify this expression, we have to apply the rule of the exponents.

This rule says that:

$a^b.a^c=a^(^b^+^c^)$

If you have the same base, the exponents can be added.

We can rewrite the expression $a.3a^3b$ as $3(a.a^3)b$

Then we have:

$a.a^3=a^1.a^3=a^(^1^+^3^)=a^4$

Finally:

$a.3a^3b=3(a^4)b=3a^4b$

The correct option is D.