Final answer:
To simplify the expression 4a² · 3a, multiply the coefficients and add the exponents of the variables. The simplified expression is 12a³.
Step-by-step explanation:
To simplify the expression 4a² · 3a, we can multiply the coefficients and add the exponents of the variables. In this case, 4 * 3 = 12 and a² * a = a³ = a³. Therefore, 4a² · 3a simplifies to 12a³.