Final answer:
To simplify the expression 4b + a², multiply the coefficients and rewrite the expression as 4b + a * a.
Step-by-step explanation:
To simplify the expression 4b + a², we apply the rule of raising a power to a power. The expression a² means a is multiplied by itself. Therefore, we can rewrite the expression as 4b + a * a. This can be further simplified by multiplying the coefficients and using the distributive property, resulting in 4b + a * a = 4b + a².